10-3: Where's Carol Vorderlem?

Lemmings: 10
Save: 4
Time: 20:00
Release Rate: 25
Skills: 2 Climbers, 2 Floaters, 6 Bombers, 6 Blockers, 10 Builders, 10 Bashers, 10 Miners, 10 Diggers

Good: An interesting and fun puzzle in which the crowd has to divide and conquer to reach all four laser gates, while the two trailblazers prepare the route and ultimately release the lemmings from their "prisons".  It is quite satisfying to save all 10 lemmings, and I like how the lemmings hit the gravity inverter at the top of the level and fall directly into the balloon.

Bad: Why on earth is the save requirement only 4/10?  I'll admit that 10/10 is pretty challenging, but 4/10 allows you to completely ignore rescuing three of the four "groups"!  The 20-minute time limit doesn't make much sense to me, either.  Even if you don't multitask the digging at the beginning, I don't see how it could take that long.

9-9: It's a hard life

Lemmings: 50 (2 entrances)
Save: 45
Time: 7:00
Release Rate: 69
Skills: 1 Climber, 2 Floaters, 4 Bombers, 4 Blockers, 8 Builders, 1 Basher, 2 Miners, 5 Diggers

Good: A nice puzzle in which the small group by the exit must dig out a tunnel for the larger crowd.  Unlike "Ice Station Lemming" in ONML, the main crowd cannot get up to the exit without assistance from the other group.

Bad: The retractable wall is virtually useless, since you cannot build in front of it.  The first time I played the level, I failed because I had the entire crowd stuck in front of the retractable wall, just under the exit, with no way to get them up.  Also, connecting a bridge to the completed miner tunnel can be a bit finicky, requiring some precise builder placement.

9-4: Booby trap

Lemmings: 50
Save: 46
Time: 8:00
Release Rate: 50
Skills: 5 Climbers, 10 Floaters, 5 Bombers, 2 Blockers, 3 Builders, 3 Bashers, 3 Miners, 2 Diggers

Good: A race to hit the switch and release the crowd a weasel-induced massacre occurs.  The switch on the way to the exit makes it so the crowd has to be reasonably bunched up, otherwise the stragglers will become weasel punching bags.

Bad: Wow, where do I start? 

First of all, the process of hitting the switch is so simple it's almost trivial.  This is by far the least interesting of the levels that have used this theme.

Next, the teleporter is glitched almost to the point of being game-breaking.  It's designed so that the lemmings turn back toward the exit as they are exiting the teleporter; unfortunately, sometimes I've had multiple lemmings get sucked back into the teleporter going the other way, returning to the start where the weasels are waiting for them.  This entire problem could have been eliminated by simply reversing the positions of the teleporter and exit, or even eliminating the teleporter altogether and just moving the exit down.

Third, it only takes two bridges to make a wall that holds back the weasels, which defeats the entire "quick as you can" concept.

Lastly, What is with the switches being in the form of those weird boxes?  This is the only level in the game in which they appear, and they don't appear to serve any purpose that can't be fulfilled by switches or laser gates.

I'm not sure it is possible to revive this thread, but it doesn't hurt to give it a try!

8-8: Take Her to Warp Speed, Captain

Lemmings: 25
Save: 12
Time: 8:00
Release Rate: 5
Skills: 10 of each

Good: Introduces the speed-up pad.  The save requirement is lenient enough that you can lose a few to the spiked log and still pass the level.

Bad: One way to avoid the spiked log is to mine and bash underneath the speed-up pad, bypassing it altogether.  This more or less defeats its purpose.  Also, although it barely works, the attached screenshot illustrates a ridiculous backroute.

This just barely works, but Mayhem 25 has been reduced to 4 builders.  A detailed solution and screenshot are provided below.

Here's my results for the Tricky and Taxing levels in this challenge.  For an extra degree of difficulty, I did the max-% solutions for all of these.  I also added one of my own favorite challenges to the mix in Taxing 15 100% No Builders.

Tricky 19: 1 attempt
Tricky 22 100%: 2 attempts
Tricky 24 100% 2 attempts
Tricky 25 100%: 8 attempts

Taxing 3: 1 attempt
Taxing 11: 1 attempt
Taxing 14 100%: 2 attempts - in the first attempt, I placed my basher through Nessy too high, resulting in a splat fall off of Nessy's nose.
Taxing 15 100%, No Builders: 14 attempts - The successful attempt was blooper-fest, yet I somehow managed to pull it off.  I let a digger go too far and ended up having to redo a section of work that had previously been completed.  Later on a miner turned off a blocker that he was supposed to free, resulting in even more skill wastage.  I ended up using all 20 bashers, all 20 miners, 19 of 20 diggers, and the last lemming exited with 6 seconds left on the clock.
Taxing 16 100%: 6 attempts - There's a bunch of frantic building early on in this one, but it's fairly simple after that.
Taxing 22 100% (2 solutions): - 1 attempt for the direct route (send a floater down and have him build a catch-bridge for the others); 3 attempts for the "over-the-top" route.
Taxing 24 100% 1 attempt
Taxing 26 100%: 5 attempts - I technically got this on the first attempt, but I used all 12 builders in doing so.  To be fair, I kept trying until I got the builders down to 10, to meet Amiga requirements.
Taxing 28 70/80: 29 attempts - This one is tough even when pausing is allowed!  There were a couple of spots in which I had to assign basher then builder in rapid succession, requiring a rapid-fire click-F7-click sequence.  I'd be truly shocked if anyone could pull this one off without using the keyboard.

I had a go at this challenge using DOSBOX, and the only one that really gave me fits was Mayhem 15.  The digger pits at the beginning required some quick transitions on opposite sides of the level.  I got most of the others pretty quickly.  I don't have any videos, but I thought I'd share my number of attempts for each level and describe a few of my own bloopers:

Wicked 4: 4 tries for 98%.  My second attempt "failed" while I was trying to rescue the last group, but the funny part is I had already saved enough lemmings from the other hatches to pass the level, so I had to reenter the level code to try again!

Havoc 9: First try

Mayhem 11: 3 tries.  My first attempt goes in the blooper hall-of-fame: I clicked on the first lemming as he approached the end of the platform, only to watch him continue to walk right off the edge.  I then looked at my skill panel and saw that I had never switched to Digger!  In all honesty, though, I found this one to be a piece of cake if you set the release rate to 50-55 and just assign diggers to every other lemming.

Mayhem 15: 11 tries for 100% (in under 2 minutes, to satisfy Amiga requirements).  My most comical failure was when I tried to quickly switch from Builder to Digger, and ended up pausing by mistake, as that icon is right next to the digger icon.

Mayhem 4: First try (100%)

Mayhem 21: First try, and yes I did make the first lemming a Climber.  After that he only needs to be assigned four skills, and only one of those assignments needed to be made as a lemming was coming out of the hatch.  Fortunately I saw this coming and was prepared for it.

Mayhem 20: Second try (the first try failed when I assigned the final miner too late and he mined under the exit instead of through the top of the bridge.)

Havoc 7: 5 tries for 100%.  The successful attempt almost resulted in a comical failure when I nearly forgot to assign climbers to the group that needed to climb to the exit.  Fortunately I caught it just in time and managed to spam-click on everyone.

Havoc 12: 2 tries for 100%.  I had a total mental lapse right off the bat in my first attempt, forgetting that the first lemming cannot simply drop down to the pedestal; he needs to build there!

Havoc 20: I saved 85% on the first try.  If not for two mistimed bombers, I would have had the maximum 88%.  It helped that I had played this level recently and remembered exactly where the first bomber had to be set to keep everyone away from the lizard trap.