Nice vids of Shadow so far.  It was one of my favourite tribes to make, due to the setting and the skillset. (the bomber being a lot more flexible than I originally thought, which compensates for having just explosions to tunnel with)

Anyway, onto some notes:

Spoiler

Shadow 3 - I spent ages trying to make that one break-proof, and I still failed   Easy to fix though, and still a neat solution. (though I think you know the correct one now, from the youtube comments)
Shadow 4 - You actually solved the falling puzzle right at the start (in your commentary) but I'm still impressed that you managed to cheese it.
Shadow 5 - Not quite the right way (this one is almost a disjoint union like L3), but another good alternative.
Shadow 6 - I didn't think a shimmier could cross over a hole in the ceiling like that, as a result you did backroute it that way. The correct one is building into the cloud to turn round and jump onto the outside wall, hopefully people will try to find out if clouds are solid. (if they haven't played the 2 cloud-based levels in other tribes)
Shadow 7 - This one has multiple solutions due to it's length (I added a 3rd rope just for that). Mine is a more thematic one (monkeying around the sewers like ninjas do) but yours works just as well.

And this leads onto a new build - please use this one, as it contains fixes to the remaining Shadow levels. (which you are about to play)

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Version 13.6 has been released
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Sports 2 (The Stadium Underbelly) - reworked some areas (notably around the trapdoor), changed some skill amounts.
Sports 5 (Dynamic Duo) - reworked the start area to remove the chance of breaking the main concept.
Sports 7 (The Gulf in Class) - reworked the first area, changed some skill amounts.
Sports 8 (Switcheroo) - reworked the bottom left corner and added some skills, altered the release rate. (it was still possible to break the main concept)
Shadow 2 (Urban Gymnastics) - moved the postbox to the right, removed a brick near the weird pit, +1 filler.
Shadow 3 (Filling Station) - removed a few bricks from under the 2nd trap tunnel. (backroute fix)
Shadow 4 (Air Raid) - extended the metal dividers between the underground trapdoors. (backroute fix)
Shadow 5 (Water Works) - added a long metal strip between the two trapdoor areas. (backroute fix)
Shadow 6 (Scraping the Sky) - partly reworked the area around the thin shaft and traps. (backroute fix)
Shadow 8 (Production Line) - added 2 exits, removed some scenery and all the bazookas, +3 bombers. (it was still possible to break the main puzzle)
Shadow 9 (Mission: Impassible) - restored the bazookas, there are now 12 of each explosion.
Shadow 10 (Pockets of Resistance) - carved out a niche in the central shaft, to ensure that no rock climbers can escape. Also +5 bombers, as it was a little too tight.

Great to hear from you again:

Spoiler

Shadow 2 - looks like the pit is causing issues. The lemming will slide into the gap, but I didn't think it would appear too small for that...I probably need to make it bigger. (and a similar gap in L5)

Sports 2 - Definitely a backroute there, taking the whole crowd across the top. Nice solution though, probably easier than the intended one. (apart from the pixel-precision miner)

Re: scenery - everything is solid except for sun, moon & stars. (and objects ofc)

The more I think about it though, the more I think I've actually made this harder than QFK2 - and that's just on the puzzles. (not counting the larger level sizes and skill counts)

What started out as a couple of fixes turned into another major update - this time going over everything. I'm hoping that most or all of the backroutes are gone*, so I've mainly been focusing on improving the execution side. (adding skills, fixing terrain etc.)

* I don't mind alternative routes, as long as there's no shortcuts or breaking/bypassing major puzzles. So those are still in, especially in L1/L10 which are like that by nature.

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Version 13.5 has been released
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Highland 3 (McLem's Drunken Dream) - the bottle of whisky has fallen off the cloud and into the water. Added 2 throwers.
Highland 7 (Artillery Range) - +3 mortars. (in case something goes wrong)
Circus 3 (Jack in t'Box) - moved the exit and surrounding ledges down a touch. (to make the ballooning easier)
Circus 4 (Red vs. Blue) - reworked most of the bottom section, reduced platformers to 6, increased jumpers to 30 and renamed it to "Don't Capture the Flag". (not sure if this fixes the backroute but it's harder to get if it doesn't)
Classic 6 (Chambers of Aquatia) - +1 basher. (to give greater control over the main puzzle)
Classic 8 (Tricks & Traps) - swapped the order of the middle & right trapdoors.
Medieval 2 (Hack & Slash) - swapped with L3.
Medieval 3 (Cave of Knaves) - swapped with L2.
Medieval 4 (Finishing the Arc) - fixed a bug that was cutting off the very top of the level.
Medieval 6 (Dungeon & Dragon) - swapped with L7.
Medieval 7 (White Cliffs of Dunder) - swapped with L6.
Medieval 9 (Tower of Maidens) - tweaked a couple of the staircases, +2 fencers. (in case something goes wrong)
Egyptian 2 (Stomp Like an Egyptian) - +1 basher. (in case something goes wrong at the end)
Egyptian 3 (Tomb of Ikea) - moved to L6. Also added/changed a few skills to account for different outcomes of the main puzzle.
Egyptian 4 (Night Boat to Duat) - moved to L3. Also removed a filler and a glue pourer.
Egyptian 6 (Wade in the Water) - moved to L4.
Egyptian 7 (Sidestepping Evolution) - moved some of the "bumps" around to make navigation easier.
Egyptian 8 (The Chambers of Cain) - removed 3 carpets and also the need for 1 carpet (to prevent one section from being cheesed). Added 3 shimmiers.
Egyptian 9 (The Plunger's Tomb) - +1 filler, -2 glue pourers, extended the lowest platform a little bit. (due to the weird behaviour in this area)
Outdoor 4 (In Order: Down, Along, Up) - +1 bomber. (I found this improves the reliability of roping where there's loose pixels around)
Outdoor 7 (The Irrigation Pond) - -2 ballooners, +1 planter.
Outdoor 10 (The Plantshaft) - +2 parachuters. (in case they're needed)
Beach 3 (Everybody Do the Flop!) - swapped with L4. Also added a pile of sand at the foot of the cliff. (to make the scooper more reliable)
Beach 4 (Fall & Rise of Reg Lemmy) - swapped with L3.
Beach 5 (W is for...) - removed the cloud near the trapdoor. (bad)
Beach 7 (Sandy Cove) - moved to L8.
Beach 8 (Dune Climbing Contest) - moved to L9.
Beach 9 (Beach Hut BBQ) - moved to L7.
Sports 2 (The Stadium Underbelly) - reworked some areas (notably around the trapdoor), +2 runners, +5 shimmiers, -2 fencers.
Sports 3 (Letting Off Steam) - replaced the tennis rackets with a snooker table. (it was thematic to see them jumping off the rackets, but harder to execute)
Sports 9 (Remote Control) - -1 miner. (not needed)
Shadow 2 (Urban Gymastics) - -2 fillers. (not needed)
Shadow 3 (Air Raid) - reworked the left side, as it was possible to cheese the falling puzzle. Solution altered as a result and the skills have been changed accordingly. Also swapped with L4 due to increased difficulty.
Shadow 4 (Filling Station) - swapped with L3.
Shadow 8 (Production Line) - reworked the very bottom (to look more like a sewer under the factory), extended the ledges a touch, -3 bombers, +5 bazookas, -1 roper. (it broke the main puzzle, so the bazooka now covers any issues)
Shadow 9 (Mission Impassible) - -5 bazookas, +5 bombers. (this is now the no-bazooka level, due to the L8 changes)
Shadow 10 (Pockets of Resistance) - -2 builders. (not that it matters hugely in a rope-centric level)
Cavelem 2 (Land vs. Sea vs. Air) - +1 stomper. (in case anything goes wrong)
Cavelem 5 (Lem of the Dump) -  +2 club bashers, +1 min. (in case anything goes wrong)
Cavelem 6 (Last Rule of Bash Club) - +1 min.
Cavelem 7 (The Lemcave) -  +2 builders. (in case anything goes wrong)
Cavelem 10 (Dinosaur Islands) - raised the first dino island up a notch (to make one bit less tight), +1 builder as a result.
Space 3 (Magno Force) - changed the blocks around the pit. (to ensure the best solution)
Space 8 (Beam Me Somewhere Shotty) - +3 mortars. (in case something goes wrong)
Polar 2 (Piste Off) - slight scenery change on the far right. (to make it look more dangerous)
Polar 5 (Eskimo Beat) - swapped the topmost igloo+bear head, +2 skiers, +2 flamethrowers. (to prevent an unreliable alternative for containment)
Polar 7 (Research Outpost) - +1 flamethrower. (it may be needed sometimes)
Polar 10 (Escape from Hawker Island) - raised the tree by the exit slightly. (to make that final section easier)

Hopefully this will be the last big update before the final release, but I'm probably going to wait and see how L2Player develops, and ensure compatibility etc. before signing it off. (if anyone else tries to or has tried to break these levels in the meantime it would be handy to know the outcome)

Another major update - focusing on everything else, notably levels that I hadn't visited since they were made:

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Version 13.4 has been released
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Highland 3 (McLem's Drunken Dream) - moved the golf course up a notch, to prevent roper spam from reaching it.
Highland 5 (Lembank Docks) - +1 thrower, -2 mortars.
Highland 7 (Artillery Range) - lowered the height of the first water pit and increased the size of the gap beyond it. (for easier execution)
Highland 10 (Ten Brown Barrels) - -1 roper.
Circus 2 (Devil vs. Strongman) - moved the exit back down to where it should be.
Circus 4 (Red vs. Blue) - lowered some sections to make the jumps easier.
Circus 9 (Roadblock) - slight tweak to the first 2 puzzle areas, reduced the height of the blue/yellow block in the 3rd.
Classic 3 (A Race of Halves) - shortened the metal block above the exit. (to shave a couple of seconds off the time needed)
Classic 6 (Chambers of Aquatia) - tweaked the exit to re-enable the bottom route, +1 basher, improved the release rate.
Medieval 2 (Hack & Slash) - made the middle trapdoor safe, added a bunch of skills and 1 min.
Medieval 3 (Cave of Knaves) - reworked the right-side trapdoors for easier execution, added a bunch of skills and 1 min.
Medieval 4 (Finishing the Arc) - reworked the far end to make the main puzzle a bit cleaner, -2 platformers, +2 archers.
Egyptian 2 (Stomp Like an Egyptian) - moved one section down slightly, improved the release rate.
Egyptian 3 (Tomb of Ikea) - removed the shimmiers and 3 carpets (they were leftovers from when the level was more complex), improved the release rate.
Outdoor 3 (Under the Growth) - improved the release rate.
Outdoor 5 (Treetop Village) - slight tweak to first trapdoor, +1 roper.
Outdoor 6 (Not Mushroom Out There) - extended the lower ledge on both sides, +1 kayaker.
Outdoor 8 (Sinkhole Rescue Team) - +1 platformer, +1 bomber.
Beach 2 (The Sand Pit) - added metal to the holding area (backroute fix), lowered the exit, -3 divers, -3 floaters.
Beach 6 (Little Fluffy Clouds) - fixed an ugly cloud. (who wants ugly clouds)
Beach 8 (Dune Climbing Contest) - added a bunch of skills for easier execution, and 2 mins.
Sports 2 (The Stadium Underbelly) - removed the pole vaulters. (not needed)
Sports 3 (Letting Off Steam) - reworked the start area slightly, +5 shimmiers, +1 platformer, -1 fencer.
Sports 6 (A Mountain to Climb) - removed the need for the 2nd arrow bridge, -5 archers.
Sports 8 (Switcheroo) - reworked the bottom trapdoor area to fix a backroute, -1 fencer, +1 miner, +1 min.
Sports 9 (Remote Control) - +2 mins.
Shadow 3 (Air Raid) - moved the filler puzzle to L5, slight tweak to skill count.
Shadow 4 (Filling Station) - tweaked one section to prevent the possibility of saving a builder.
Shadow 5 (Water Works) - major rework of the middle+right sections to fix a backroute and add the filler puzzle from L3.
Shadow 7 (Sewers Smell Bad) - +1 roper, -5 builders, +1 bazooka. (gives a choice of methods while making it slightly less of a slog)
Shadow 8 (Production Line) - +1 roper, +2 bombers. (in case something goes wrong)
Cavelem 4 (Ruined Temple) -  moved the 2nd dino and the ledges slightly (for reliability), +2 stackers.
Cavelem 5 (Lem of the Dump) -  removed the ledge under the carcass to fix a backroute.
Cavelem 7 (The Lemcave) -  reworked the trapdoor and dino areas a little, +5 stompers.
Cavelem 8 (Up in the Jungle) -  improved the right-side trapdoors, added some skills.
Space 4 (Orbital Bombardment) - removed the middle block on both outer ships. Also removed the mortars and added a bunch of bazookas+jetpacks to make it a full bombardment now.
Polar 2 (Piste Off) - reworked the bottom section to make this the no-roper level in the tribe. (see L9 changes)
Polar 4 (It's All Downhill!) - lowered the cavern above the exit, shortened the topmost dig, -1 roper, -1 stacker.
Polar 6 (Ice Box Challenge) - lowered the topmost trapdoor, -1 min.
Polar 8 (The Crevasse) - slight rework of the side caves, -1 climber, +1 flamethrower, +1 min.
Polar 9 (Avalanche Rescue Team) - added a new puzzle by extending the top right cavern to the edge, +1 roper, +5 flamethrowers, -1 scooper.

As for the final release, it'll probably have to be after L2Player - while savestate DOSBox is fine for this pack, I get the feeling that the bigger level sizes have put people off (due to more moving parts), and as a result L2Player's framestepping should make it appeal more. In some ways it kinda feels like the L2 equivalent of advanced NL packs, where the player aids are pretty much required. (despite me avoiding really high-execution moments and pixel-precision puzzles)

Quote from: kieranmillarI always was worried that QFK2 was too focused on difficult puzzles where people would just get stuck a lot until they figure out the "trick", a level style that actually only crops up rarely in official Lemmings games.

The main reason for that is because there are so many skills and tricks that can be done (either on their own or with a combo) - whereas with L1 it's mainly the glitches/exploits or advanced tricks that only cropped up in the age of internet video sharing.

I've done exactly the same regarding tricks/puzzles (esp. with the different skill combos compared to QFK2), and thinking up those sort of puzzles was the thing I enjoyed most about making this pack.

Another candidate I'd like to see retained is the ice physics - where the lemmings slowly slip & slide their way across. (every back & forth cycle sees them end up 1 pixel further forward, in the direction they were facing when they first went onto the ice)

I found this very useful for designing Polar levels with, as it lets you auto-contain the crowd for a fixed amount of time.

This almost seems like deja vu, but having done my own full L2 game, I am also going to post my thoughts on the skills. No rankings here though - instead I'm going to group them and discuss generally without any specific criteria, though still from a designer's point of view:

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Major Mobility
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This is the biggest category, so I shall begin here, with ascent:

Climber - it still does it's thing well, but I did struggle to use them in Polar due to the natural terrain discouraging the use of vertical walls (and I often went with another way of ascending that didn't require that). Many of the other lemming-separator skills are easier to set up, but you can still do a fair bit with this. (and containing them afterwards is still a puzzle in itself)
Rock Climber - pretty much fully supersedes it's ancestor and also has two of the best combos in the game (Shimmier and Parachuter), albeit at the cost of being harder to contain and prone to losing it's dangle animation if too many sprites are being used on a level. It also has a weird quirk, as it won't use the crawling glitch or climb over vertical arrows. (whereas a regular climber will)
Magno Boots - these are great to have, but very difficult to plan around...as they cannot be stopped by ANYTHING except another skill use (which made one level a bit more fiddly than it should've been). Combos nicely with the other signature Space skills, though.

Onto the plethora of flying skills:

Superlem - nothing is mightier in the air until you realise that it's a bit too powerful and can lead to backroutes galore (which made me remove it from 2 levels). Fun to use though, and bonus points for not using the fan.
Icarus Wings - I was pleasantly surprised by this, as it proved to be highly flexible but also more controllable due to the low speed (no faster than a walker). It does suffer from being over-sensitive though, as do many fan skills.
Ballooner - another favourite of mine, particularly in Outdoor with another strong Parachuter combo. The height of the thing makes you tread carefully, and it's not too bad with the fan either.
Magic Carpet - unusual in several ways, particularly by being quite hard to stop...which led to some interesting designs. Not very flexible due to the fixed direction and fan trickery needed to operate it, and it's a bit unpredictable against vertical walls, too. (sometimes you can get it up a stomper tunnel, other times it'll glide down a wall and come off at a slight touch)
Hang Glider - awkward due to the generally slow fan response (especially when launching) and yet when the fan is blowing at full pelt it will shoot off upwards real quick. Like the carpet, the execution and fixed direction make it inflexible and less useful than the other fliers, though there are at least a couple of good puzzles to be made with it.
Jetpack - good and bad for the astronauts. Very difficult to control and especially to gain height with, though the fixed facing direction is useful here (unlike the carpet/glider). But what saves it from being the worst flying skill is the fact that it works very nicely for other non-flying purposes.

Coming down from the sky, we have the fall-breakers:

Parachuter - this is amazing, lots of puzzle potential here...especially when paired with the Rock Climber or Ballooner. It can even trigger off explosions, which leads to chaos (if bumping into walls weren't enough). Bit over-sensitive to the fan, but a minor flaw in this case. One of my favourite skills for designing and operating.
Slider - this also has lots of puzzling to go with the safe landings, in fact the awesome Shimmier combo and constant changing of direction by the lemming leads to a large amount of options. Another great skill for designing with. (just don't try to dangle off a builder bridge, as it needs 2+ pixels to do so)
Floater - the super-cali-brolly is left behind, as you can't do anything else with it except for the old Cascade trick from L1 (and even that isn't fully reliable, as it's possible for a lemming to go splat while you assign the skill). Especially problematic with the fixed 80x20 size limit in Classic, but even in a 20x80 Beach level there's no puzzle to be had.

Finally, we go splash:

Swimmer - water skills are not good for puzzles, but this is quite nice...as it's a permanent skill that gives you some options (being able to go across water multiple times is very handy). It's also quite novel to see lemmings constantly in the water and not drowning. (even allowed me to do a naughty thing in one level)
Surfer - this can be cool due to the fact you can turn it around and play with it (just don't leave him stationary for more than 2-3 secs), but not much else.
Kayaker - a one-trick pony...also annoying because there has to be a decent gap between multiple lemmings that need to paddle. (it's prone to failing if not, though it might depend on what stage of animation the kayak is at)
Skater - also a one-trick pony...except it's a permanent skill that only works in Polar. It does have one powerful use though, which is escaping the "Ice Timer" - a temporary containment area that takes advantage of the ice physics.*

* Basically, the lemmings will slip & slide their way very slowly across the ice (1 pixel at a time) - so smaller patches can be used to contain them for a while (very useful for race levels). Anything longer than 3-4 grid blocks and they'll take too long, which makes it back into a trap as normal.

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Minor Mobility
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This includes skills that provide a small effect. First we have propulsion:

Runner - it does have a nice amount going for it...speed, the little hop and the jumping combo - but I used up all the ideas I had for it in a single tribe, so that's where it stayed. (shame really, as it's a skill I use quite a bit IRL)
Jumper - the most-used skill in the original game (78/120 levels) and is always handy as a generic skill for speeding and cancelling other skills etc. but it's really just there for convenience.
Shimmier - does everything the Jumper does (including the Runner boost) but also crossing low ceilings, and has two of the best combos in the game (Rock Climber and Slider). Lots of puzzling and lots of convenience...without a doubt, one of the most important skills.
Hopper - total rubbish. If you're not using it for it's intended purpose (those obvious stepping stones), it's pretty much a Jumper with terrible range that keeps on going.

And now we have to deal with the useless skills:

Pole Vaulter - a complete gimmick with exactly 2 uses...vaulting up on top of a wall that needs a massive run-up area (which always says "this is the only place to vault a pole"), and cancelling other skills.
Roller - my favourite useless skill, as it's quite fun to play with. It has some subtle uses (including skill prevention) and I made some nice combos with it, although it's sometimes hard to click another skill on due to it's high speed. It does appear to be inconsistent when launching off something, but it actually depends on where the lemming is when you click it. (notably on builder bridges)
Skier - similar, but much more controllable due to it being slower...and I was surprised by how much I used it for various things. The infamous unreliability comes from trying to do ski jumps - on the flat or downhill it works fine.
Diver - everyone else's favourite useless skill. Doing the flop is quite funny, even on the flat it can go through traps, it's great for cancelling other skills and I did manage a few puzzles with it. (finding uses for useless skills is great)

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Containment
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Not much to go through here:

Blocker - only works in Classic and is awkward because of the difficulty in releasing them...which appears to be even harder when facing left instead of right. (most apparent on builder bridges)
Attractor - a neat idea for easy containment...but unreliable to the random delay of it taking effect, and the difficulty of releasing it when too close to the dancers. It's nice for grouping up lemmings to do certain puzzles, or holding a lemming in place for later use.

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Major Construction
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And now for the 3 most-used skills, plus one more:

Platformer - of the two bridging skills, I found myself using this more for puzzling...it just seemed to combo better with a lot of skills. It also covers a greater distance, so less time is lost and less are needed. Only snag is the lack of height gain (unless you spam them like I did in one level) so I often had to rely on terrain, on-level extras or other construction skills to rise up.
Builder - still one of the most important and versatile skills in the game, but it does take a lot of them to get anywhere (which sadly is discouraged due to the general dislike of builderfests in L1). There are some lovely combos to be had, though. Both skills were used in 5 tribes, but the Platformer edged it by 1 single level. (44 to 43)
Roper - this is powerful but can also be a bit unreliable. It's range seems to be a square rather than a circle, and while it's easily the best skill for going upwards it's also quite difficult to plan around (and ofc there's the infamous roper glitch on natural terrain). The limited range can be used to control it and create puzzles though, it combos very well with the Scooper in particular, and overall it was worthy of being used in 4 tribes (the only such skill).
Glue Pourer - bit awkward to use due to being entirely dependent on terrain unless you have a Builder around (hello space glue), but that can also lead to some interesting designs and puzzles. It also has another important use, too.

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Minor Construction
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These are the ones that just add a small bit of terrain or play a lesser role:

We'll start with trajectory-based stuff:

Thrower - only really used in that 1 Highland level in the original game, hence it's appearance in Highland here too. There's not a huge amount you can do with it, but the shape/size of the rock means that there are some puzzles to be had. (though sometimes you need quite a few of them)
Spearer - similar type of thing, but the spears are too thin for chaining them together...although this combined with the long length means that you never need loads of them (easier to execute). Overall it's a bit more limited than the Thrower, but I did manage to use it a surprising number of times.
Archer - this is one of my favourite skills in the entire game. Some will argue about the execution requirement...but if you can finish the notorious final level of Sports in the original game, then you've learned the skills to reliably place a vertical arrow. In general it can occasionally mess up like the Roper (though mostly reliable), but only gets difficult if you aim for a spot that's too high and too far away. I found so many uses for arrows across the 2 tribes it was in, definitely one of the most versatile in my book.

Moving onto the ground next:

Planter - this thing only got used once in the original game, and while it is definitely flawed (the facing direction matters a LOT), it does have some neat uses and combos. (in fact you can do a number of different things with it)
Sand Pourer - it doesn't look like much, but it is actually quite effective once you get used to designing with it. There are some great combos and puzzles to get with this, even though you sometimes need quite a lot of them. (having it in tribes without upwards construction really does make minor skills like this and the Archer shine)
Filler - the weakest of the pots. You can only really fill in pits and block up traps (which almost feels like a meme in Shadow), but I did manage some neat puzzles with it. (despite the fact it can take a lot of them to be effective)
Stacker - a good solid skill to have, enough to elevate it into 3 tribes (and the top 10 most-used in ToS, which also happens to be the 3-tribe club). Not just for containment, there are some good combos too...particularly with some of the worst skills and the on-level extras.

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Major Destruction
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This is the other big category, which covers all the tunnelling skills:

Basher - a staple skill that does well as it always does. Can't really say much else (because I'm not an expert on advanced tricks/glitches), but there's always room for a tunneller like this. (also did some nice combos in Egyptian)
Fencer - does the same thing but with a slight upwards angle (which does have puzzle potential) and is less sensitive to stopping due to lack of terrain (which means you can also start it with less terrain in front of you). The first bit of the tunnel is instant (nice for getting rid of small blocks/stacks) and it combos nicely with the Miner in particular.
Club Basher - not much more than a basher that just carves out a bigger tunnel more slowly, but the massive swing can have a massive effect on puzzles. It's decision-making is a bit wonky for deciding when to stop, but this also depends on the wonkiness of the terrain.

Miner - always one of the most important skills due to it's slope (thankfully there wasn't an L2 for Win95 to replace it with steps) although tbh I did struggle to do much in the way of complicated tasks with it. Maybe because I'm not that classic-minded (there's only so many times you can send a lemming round the level to mine down through a big block), but I found myself using the Scooper more for big tunnelling tasks and the Miner more for small precision tasks. Doesn't take away from the usefulness or versatility of the skill though.
Scooper - not a huge fan due to the tunnel being steps instead of a slope, but it got into 3 tribes due to theming (soil, sand, snow) and it also creates a wider opening which allows it to go through floors much better than a miner. Doesn't play well with classic skills, but with the Roper it's rather good - combined with the steeper angle (which is the main thing to like) it takes up a lot less room than a miner, massively increasing the different types/sizes of areas it was usable in.

Digger - vertical tunnelling is a bit less useful in L2, but this is still a solid pick...particularly when climbers are around. It's still possible to do some nice puzzles with it, though it's traditional containment niche is gone without directional selection.
Stomper - identical except for being twice as fast and more prone to stopping due to lack of terrain...sometimes you want the speed, but most of the time you want the precision of a digger. In other words it's not worth bothering with unless you're trying to use every skill. (you can exploit the fact that it does 2 pixels at a time instead of 1, though)

Twister - the Marmite of all L2 skills. I personally quite like it, simply because the tunnel-anywhere-you-want nature of it leads to some good puzzles and combos. It's just a shame it's so hard to control, to the point where everyone gives up in frustration...so the best I could do was give out plenty of spares and plenty of room. (except in the odd case where having spares would break the level)

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Minor Destruction
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This section covers limited-range skills:

Laser Blaster - technically a tunnelling skill, but it has a limited range and can't really be used like the others so it gets classed as a minor. It is possible to go up the tunnel with certain skills (I used it this way in both it's tribes) and I was particularly pleased with one Circus level that used it in a more complex way, but most of the time it's just for freeing the crowd from underneath.
Flamethrower - a decent short-range blaster, and is unique because it's instant (this can be good or bad). It sometimes requires a bit of precision when linking it up with bridges or other tunnels (due to the cone-like shape of the hole it makes) but on the whole it blows all hot and no cold.

Finally, we reach the explosions:

Bomber - I was quite surprised by this...it is incredibly versatile. You can use it to tunnel across, down and anywhere in between...and without the knockback of the other explosion skills (instead he gets flung up and lands facing the same way). You do need a lot of them to tunnel like this (certainly when I used it this way in Shadow) but low skill counts were not a limitation I wanted to use.
Bazooka - this is limited to going only across and slightly up (apart from two novelty levels I made), so it's only standout feature is blowing holes in walls from far away...which is nice for avoiding the knockback and creating a step for containment.
Mortar - this is a bit better as you can go diagonally upwards, rescue from below and there's also some sneaky less obvious puzzle uses.
Exploder - this is the worst by far. You can't use it to fall-bomb in Classic (it's bugged) and ofc it kills a lemming. I did manage to use it in a couple of interesting ways, but it's no surprise that it's the least-used skill in ToS. (only 5 levels)

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Extras
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Finally, we come to the interactive features on the levels themselves. These exist purely as gimmicks in the original game, but I went out of my way to create actual puzzles with them. As a result, I counted them as extra skills and imposed the same conditions on usage. Starting with the launchers:

Cannon - the best of the launchers for creating puzzles IMO, due to the decent trajectory. Fire rate is a bit slow, which often led me to use multiple trapdoors. (in order to reduce the number of lemmings using it)
Catapult - a bit unwieldy and has an even slower fire rate, but they do fling a hell of a long way. (which formed the main principle for the final Medieval level)
Dinosaur - has a much faster fire rate but a much lower trajectory...consequently I wasn't able to get as much puzzle out of them compared to the bigger launchers. Facing direction is also retained (unlike the above), which adds another problem to solve.
Flicker - aka that thing that looks like a green snail but isn't (consequently I didn't discover it until I had much of Outdoor completed, which led to me shoehorning it into a couple of levels). Same fire rate and trajectory as the dino, but with the added problem of having to drop the lemmings onto it from above (or bridge onto it from the side) in order to fire it...although this does avoid the dino's problem with facing direction.

And then the rest:

Steam Jet - I found these to be the most interesting extras, despite that godawful first Sports level in the original game doing it's best to put everyone off (by being stupid and chaining them). Not only is there a choice of all 4 directions, you also have the option of valves to turn them on/off...which is a great way to stop backroutes (at the expense of saying "this is the correct route") and you can even make puzzles with them.
Trampoline - they're a bit tricky sometimes (the part of the trampoline you land on determines the bounce) but it's a good way to force the lemmings to spread out, along with fall-breaking and some limited puzzles. (I'm particularly proud of 2 levels where I did something weird with them)
Teleporter - does as you'd expect, and there's some good puzzles to be had on the facing direction when going in. Not to mention they can take you anywhere, including places that nothing else can reach.

Chain swingers are completely useless, so I took the piss and gave them a use...as scenery.
(they are actually solid objects, but using them as platforms in the playable area can cause confusion)

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So there we have it. I really enjoyed making this pack, and getting the most out of each skill. It's great that the pack turned out so differently to QFK2 despite the main concept being the same (which I still feel a little bit bad about), and I hope to see more packs in the future. (along with L2Player hopefully doing what NL did for L1)

Another update, this time focusing on the 10-trapdoor levels that end each tribe. These are meant to be an epic finale that fits my design philosophy (which favours innovative ideas/concepts) along with a review of what you've learned from the tribe. I really want these levels to work, as it's such an unusual concept that really changes things up. I've shifted some of the new tricks/puzzles into other levels wherever I could, along with making some improvements for reliability and execution. (as the logistical challenge is great enough with these levels)

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Version 13.3 has been released
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Highland 10 (Ten Brown Barrels) - added metal to the thin shaft (to prevent twistering all the way down) and 2 mortars for flexibility.
Circus 10 (Deca-Dance) - added metal to one trapdoor, and 3 ballooners to cover any mishaps at the bottom. (I really wanted to add more twisters, but doing so would break the yellow trapdoors)
Classic 4 (Bridging the Gap) - added 1 builder and 2 diggers, to cover all possible mishaps with the climber.
Classic 5 (Old Ways, New Tiles) - reworked the right-side trapdoor area and added 3 climbers, to allow more reliable ways of releasing the blocker.
Classic 7 (Stepping Up and Down) - added 2 builders and 1 climber to increase the margin of error. (also small blocks to prevent the new backroute)
Medieval 10 (The Siege of Lemcastle) - compressed the top section a little. (not that it really changes much apart from looks)
Egyptian 8 (The Chambers of Cain) - reworked the top to accommodate the puzzle from L10.
Egyptian 10 (Mandatory Pyramid Level) - moved the puzzle in the bottom-right corner to L8 and simplified the area. Removed 2 stompers.
Outdoor 10 (The Plantshaft) - cosmetic changes to the exit area, which also helps the roper.
Beach 10 (Artificial Resort) - reworked the skillset a little, to hopefully offer more pointers.
Sports 4 (A Mountain to Climb) - moved back 2 places to L6.
Sports 5 (Hold the Line) - moved forward 1 place to L4.
Sports 6 (Dynamic Duo) - moved forward 1 place to L5.
Sports 7 (The Gulf in Class) - added the puzzle from L10, replaced the large red ball with a small white ball (to make the first arrows easier to place), also added skills to ensure that the end tunnel can be done reliably.
Sports 10 (Mastered Doubles) - replaced the puzzle in the top-left corner with a different one (moving it to L7), tweaked some parts of the level to make things a little more reliable.
Shadow 2 (Urban Gymnastics) - slight tweak to one of the climbing sections. (in case you don't know about shimmying directly onto an upward 45° slope)
Shadow 10 (Pockets of Resistance) - altered the amount of construction skills, to focus more on ropers with the builders as support.
Cavelem 10 (Dinosaur Islands) - tweaked the bottom section, which also enables the double-dino-flick to the exit area. It should now be much clearer where to build, as well as consistent enough to avoid a spare builder breaking the exit puzzle. Skills altered as a result, notably 5 less builders are required now.
Space 9 (Space Glue Factory) - added some metal blocks to the underside of the top section, to make the fiddly part easier.
Space 10 (The Colonies of Desyat) - tweaked the long underground cave and enlarged the metal box above it, to make things easier.
Polar 10 (Escape from Hawker Island) - slight tweaks to the mini-caves under the ice patch, to make it a touch easier.

I've also updated the savegame file (save.dat) so it has the correct data now.

In case you're wondering about Classic 10, it didn't need any changes. Thanks to geoo's video, the solution was altered last time round and I think it's spot-on now.

Quote from: Simon on February 15, 2022, 06:35:27 PM

Two-player lemmings would be a great game nowadays? It certainly is.

It was back then...however they talked about balancing the 2P levels by drawing them out, yet I distinctly remember the green player having a big advantage in nearly all of them. (only the asymmetrical level 12 favours blue iirc)

Another fixing/tweaking pass, mostly focusing on tribes that I hadn't really gone over in the absence of playtest reports (these are really important for finding backroutes that I haven't found), and one tribe that needed a bit of work in general:

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Version 13.2 has been released
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Medieval 2 (Finishing the Arc) and Medieval 3 (Acrobatic Outlaw) have swapped places with Medieval 4 (Hack & Slash) and Medieval 5 (Cave of Knaves).

Circus 5 (Across the Abyss) - removed the attractor and 1 min. (there is another way to stop the cannon for a while, one that doesn't clump the lemmings up and harm one of the solutions). Also added another trampoline, to make retrieving the platformer lemming easier.
Medieval 5 (Acrobatic Outlaw) - added 1 roller and dragons to the top section. (after finding yet another roller trick while fixing a different level)
Medieval 6 (Dungeon & Dragon) - moved the left trapdoor onto the sloping ledge, added 1 archer (slight improvements).
Medieval 9 (Tower of Maidens) -  filled in 2 gaps, altered the amount of several skills. (this prevents the builder puzzle at the top from being backrouted, along with streamlining the rest of the level)
Medieval 10 (The Siege of Lemcastle) - removed 4 platformers (after realising you could easily backroute it), added 1 miner/stacker, made some improvements to the far-right area.
Egyptian 6 (Wade in the Water) - removed 1 small pool, and extended 1 medium pool.
Outdoor 2 (Race for Life) - shortened the wooden ledge sequence, to tighten up the race a bit.
Outdoor 4 (In Order: Down, Along, Up) - removed 1 ledge, extended the vine ladder and tweaked the final bit, to streamline it a little.
Outdoor 9 (Swamp Thing) - reworked the right-side trapdoor, to accommodate the roper puzzle from the next level.
Outdoor 10 (The Plantshaft) - moved the roper puzzle to the previous level. (it's a bit cruel to spring it on you right at the end)
Beach 7 (Sandy Cove) - made the ceiling flat, in order to prevent a possible backroute. Also fixed a bug in the skill set that made the level impossible...it now correctly has divers instead of floaters. (I hate the way that L2 screws up the skill display on the level intro screen if any 0-skill boxes are present, forcing me to rearrange them on the editor when a level is finished...which is what caused this bug)
Cavelem 7 (The Lemcave) - removed all the upper ledges from the middle section of the cave, to prevent possible backroutes.
Cavelem 9 (Devolution of Lemmings) - reworked the bottom slightly, removed 2 builders. (to firmly remove any chance of backrouting it, but still with a spare to cover a particular gap that's tricky to do in 1)

I've also added a copy of my savegame file (save.dat) to the zip, so that levels can be skipped if you get stuck. It also ensures that Classic will have the right number of lemmings on each level.

A lemming.

Mayhem 28 - I can't remember exactly which 2 pillars it was, but it definitely wasn't a walk-off.  It might even have been a dig-down from on top of the pillar...it's so long since I saw it, but I do remember my friend showing me that as the solution. (and me then wondering how to beat the rest of the level to reach the real exit)

Wicked 2 - Unfortunately not...all I can remember is not having to do the last awkward bit. (where you build into the overhead brick and bash through)

Multiplayer 5 - The first screenie looks like the right place...didn't think it was just a death glitch, though. (could've sworn it was an actual exit)

Anyone remember these? There were 3 in total IIRC:

Mayhem 28 - between two of the small pillars along the bottom section. (L1)
Wicked 2 - in the big pit at the end. (ONML)
Multiplayer 5 - partway along the bottom (starting) section, on the blue side. (ONML)

My memory is a bit fuzzy on the exact location of the first two, but I definitely remember my friend showing them all to me.

I've mostly been doing other stuff since the release, but I have had a look back at various levels that I wasn't entirely happy with (mainly in the tribes that haven't been playtested by others yet) and made some changes....also discovering a few bugs along the way.  So here's a new version with various improvements:

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Version 13.1 has been released
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Space 4 (Defying Gravity) and Space 5 (Orbital Bombardment) have swapped places.

Medieval 10 (The Siege of Lemcastle) - made some small changes around the middle of the level, to try and improve the flow a bit. Also added 2 builders and 2 platformers for flexibility. (using up every skill isn't a priority in this one)
Outdoor 7 (The Irrigation Pond) - re-added the 3rd trapdoor (there was originally 4 before release) to stop a backroute.
Outdoor 10 (The Plantshaft) - made the bottom left trapdoor safe, removed 1 roper. (wasn't needed and could ruin 1 puzzle)
Beach 9 (Beach Hut BBQ) - reworked the main puzzle in order to save it, also removing 10 sand pourers. The new version is much quicker to complete, so the time limit has been reduced. (it was way too high anyway)
Sports 6 (Dynamic Duo) - fixed the release rate to what it should be. (how this happened I have no clue. On one of the best levels too)
Sports 7 (The Gulf in Class) - moved the chain swingers to another level, as it was causing sprites to disappear. Also reworked the puzzle slightly, in order to remove dependence on an obscure trick that is discovered in the previous level.
Sports 8 (Switcheroo) - added a block to the right-side of the water, for the same reason as above.
Shadow 3 (Air Raid) - lowered the tower block slightly and reworked the underground section a bit, in order to save the final puzzle. (by making the builder+roper use consistent)
Shadow 4 (Filling Station) - reworked the main puzzle in order to save it. Removed all the bombers, plus 4 bazookas and 2 rock climbers.
Shadow 6 (Scraping the Sky) - improved the upward section a little, speeded up the release rate greatly.
Shadow 10 (Pockets of Resistance) - removed the water and 6 fillers.
Polar 5 (Eskimo Beat) - extended the water trough, added metal down to the 2-igloo platform. (backroute fix)

Shadow for me, followed by Space. Love the theming of both, and even more from a designer's perspective...as the original game didn't do justice to either of these tilesets. Medieval was also a pleasure to handle, given it's looks.

Outdoor was definitely the hardest to work with (so horrible to align the brown rocks), followed by Cavelem (no vertical rocks or big solid blocks of terrain) and Beach (no 45° slopes).

Probably some of the bigger L3 levels, mainly because the engine itself is so annoying.  For L1 it would be something like Save Me (super tiny ledge drops) and for L2 it would be Evolution of Lemmings. (the last thing you want to do with a jetpack is get it up through a tiny hole)

Quote from: Ron_Stard on November 28, 2021, 12:46:56 PM
"Take Up Archery", from Lemmings 2, is the hardest and most annoying level of all the saga. I'm sure most players would agree with me

For me, there was actually a 7-year gap between first playing L2 and finishing L2, thanks to this level. However, I found it much easier to repeat when I played it through 20 years later (mainly because I can fire vertical arrows reliably and remembered the right spot to throw 2 spears from). Definitely a nightmare first time around, but I think the 9th Cavelem level has the hardest execution trick in the game. (see above)