NOTES

Nuke glitch calculation:	S = PL/(100-P)    (rounded up)

where S = number of lemmings to be saved
	L = number of lemmings lost (or "not saved")
	P = percentage requirement for the level (the number displayed, NOT converted to a decimal)

The number of lemmings released is (S + L)


+--------------------+
| LEMMINGS -  49/120 |
+--------------------+

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FUN - 20/30
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1: RR97 instead of 99 since it means each digger gets through another pixel before the next one has to dig. Second-to-last lemming frees the one before it, thus gaining one more pixel of ground off what would otherwise be a spare digger. Last lemming slips through at the earliest moment possible.
Time: 0-14 (10%)

2: Nothing to this one at all. Used the nuke glitch to milk a couple of %, just for the LOLs.
Time: 0-17 (10%)

3: RR97 again - this time to avoid problems with lemmings passing through blockers. Worth one frame there to save 4 on a pass-through.
Time: 0-18 (10%)

4: Just a matter of how far you can push the rate before lemming #3 jumps out of the miner pit.
Time: 0-34 (100%)

5:  No real strategy to this one - it's a frantic scramble to the exit.
Time: 0-34 (10%)

6: The first two of the three saved lemmings turn around just before the explosion, which compresses the group enough for a blocker to force them through the wall. 3/12 = 25%.
Time: 0-17 (20%)

7: The bridge on the left allows lemmings that turn around to build and go back the right way. These guys are barely clickable when I tell them to build, but barely is good enough. :-) I make use of all the builders in order to release the lemmings as soon as possible, and the nuke glitch comes into play as well.
Time: 0-42 (50%)

8: Proximity to the exit means I can get through with just one lemming by the nuke glitch. Two uses of the miner glitch get the lemming down far enough to turn with a builder.
Time: 0-05 (95%)

9: Percentage requirement is too high for the nuke glitch to take effect here. Building under the entrance makes too little difference to matter. Standard solution away!
Time: 0-27 (90%)

10: Similar to Fun 8, but this time it's quicker to use a blocker since the percentage required is low.
Time: 0-08 (50%)

11: 30/36 = 83% with the nuke glitch. Steel-digging with blockers and frantic bashing once I'm past the one-way triggers get me through without delaying the last lemming.
Time: 0-23 (83%)

12: I've carefully carved out a path that avoids jumping and falling, and made sure no one fell behind the 40th lemming. The miners are placed so that each takes away the floor needed by previous ones, causing them to stop.
Time: 0-27 (50%)

13: Four speedrun solutions for the price of one :D. At RR99, the last 10 lemmings can get away without digging themselves. The rest can do whatever, as long as they survive.
Time: 0-43 (100%)

...

17: The left group is too far away to matter here, and despite my best efforts I couldn't get a lemming from the centre-left to overtake the 8th from the centre-right, meaning I may as well ignore that entrance too. Just sneaks in under 22 seconds, and there's nowhere near enough skills to dig out enough steel to reduce the fall and improve on this time.
Time: 0-21 (40%)

18: Two lemmings turn back, but both rejoin the crowd ahead of the crucial 50th lemming.
Time: 0-44 (71%)

...

24: Mine to the exit, job done.
Time: 0-24 (66%)

25: The miners take out one pixel of terrain behind it which would otherwise force the lemmings to "jump" across the lines in the grid. Lemming #40 gets a perfect walk to the exit.
Time: 0-33 (50%)

26: This method of speed-building with two lemmings is just one frame per two builders slower than the fastest possible speed-build, when going right. And since this level only has two lemmings to work with, I'll have to settle for that. The height increase on the second gap is a real headache, and I really don't know if there's a better way than the one I used.
Time: 0-27 (100%)

27: ccexplore gets credit for finding this solution, which led me to seek out other nuke-glitch solutions and possibly even sparked my interest in speedrunning Lemmings. Two floaters and nuke glitch, easy as pie.
Time: 0-14 (50%)

...

30: We start so close to the exit that only one lemming is needed. Frame-by-frame digger alternation is handy.
Time: 0-07 (66%)


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TRICKY - 15/30
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1: A bit of experimentation and a whole lot of calculation led to the setup you see here for building over the gap. Getting a pass-through blocker on the left side was a tough task, but well worth the effort. To conserve bashers and hurry along some lemmings, I converted some lemmings to walkers by digging under them and then making them block in the air. 21/42 with the nuke glitch.
Time: 0-45 (50%)

2: See Fun 13.
Time: 0-48 (100%)

...

9: There's not enough diggers to go the whole way through with the cursor glitch, so I need something else to take out the last 4 pixels. Miners with blocker interference do the job. Getting everyone to face the right way at the end is a tad tricky, as is finding a gap in the skill assignments to turn my builder at the top.
Time: 0-06 (93%)

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11: Surprise! No sliding trick here. Its much easier to create a ramp with bashers, and (hopefully) faster, since the sliding trick loses a lemming (the "launcher" gets stuck at the bottom), which would require 5 more lemmings to be released to make up the required percentage. Plus coralling a bunch of lemmings in that space would be nightmarishly difficult, if it's even possible. One lemming is delayed slightly because it is unclickable when I need to turn it, but as far as I can tell that won't affect the time in seconds. 16/19 with the nuke.
Time: 0-18 (84%)

...

15: Whether I let a lemming turn back (as happens here), drop the rate temporarily to prevent this, or use another bomber, the end result is the same.
Time: 0-13 (60%)

...

17: This just comes down to pushing things as far as possible without anyone turning back.
Time: 0-29 (96%)

18: The bomber goes off at the earliest possible moment that will allow the lemmings to survive the fall, and the digger merges with the back of the group. I use both builders to turn lemmings so that I can empty the trapdoor sooner, and the gap in release prevents lemmings from falling straight to the floor and splatting after the explosion.
Time: 0-22 (90%)

19: Credit to ccexplore for finding the trick with the basher and miner, without which this level would take well over a minute. Climbers and floaters are used to great effect in allowing the last lemming out sooner.
Time: 0-49 (100%)

20: The timing on this level is a tad harsh - to sneak in under 55 seconds, I have to save the first 76 lemmings that enter the level. There's not enough time to wait for an extra one on the end to cover a lost one. I do get a couple of spare frames for falling and/or jumping, which I make full use of by digging a pit. The first blocker kindly takes out the one-way arrows for the miner, and the second one (the 77th lemming, which doesn't need to be saved) turns back the tunnel basher at the end.
Time: 0-54 (95%)

...

22: In the absence of blockers and cheesy turnaround tricks, I have to resort to the slightly-less-cheesy wall of builders. This has the added benefit of making all but two builders turn back and go to the exit. 18/20 is 90%.
Time: 0-10 (90%)

23: This one's all about keeping alive as many lemmings as possible. Because of the forced 99 rate and the bizarre floater mechanics, it's only possible to get 6 climbers stuck with the basher.
Time: 0-36 (60%)

24: This one works out nicely. The blockade is cleared before the 75th lemming gets there.
Time: 0-50 (93%)

25: Fun fact: if you tell a lemming to dig when it has no ground underneath it, it will fall down straight away. It doesn't even transition into a walker. This is the key to gaining the last couple of frames needed to drop below 50 seconds. The rest is simple.
Time: 0-49 (12%)

26: Same as Fun 9, but this time I gotta wait for everyone to exit.
Time: 0-29 (100%)

29: A simple exercise in levelling the terrain. Building under the entrance saves 4 frames in falling time, and the miner glitch comes in handy for turning builders.
Time: 1-13 (98%)


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TAXING -  5/30
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19: The replay for Fun 18 works equally well here. 3 more seconds needed this time due to the greater percentage requirement.
Time: 0-47 (91%)

20: Now this is a rarity - there's time to build under the entrance and completely eliminate the fall, and the last required lemming gets a perfect run to the exit. Barring any undiscovered speed-travel glitches, this one can't be improved by even one frame.
Time: 1-21 (87%)

21: Blockers cancel both steel and trigger areas, which saves me having to build over the flamethrower.
Time: 0-34 (100%)

22: The blocker at the start cancels the steel area which extends above the steel terrain, and allows the digger to go down one pixel further so that the lemmings don't jump out before I need them to. The two floaters complete a safe landing platform as fast as possible (with help from above in digging out the ledge), and the crowd arrives at exactly the right moment. 12/15 with the nuke. Fortunately this is DOS and not Amiga, otherwise I'd need 100%.
Time: 0-21 (80%)

...

30: WAFD, same deal again.
Time: 0-53 (100%)

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MAYHEM -  9/30
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3: I was pushed into finding a quick solution method for this level by L++, which has a much faster timer than DOS and makes the "standard" solution (my usual solution at least) impossible. This (minus the blocker) was the result. By using the blocker, I can start the basher further back (he has to take two swings in any case), and the smaller dent in the wall means 6 frames less walking for the trailing lemmings.
Time: 0-38 (100%)

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7: Once you take away the skills that are absolutely necessary to solve this level, there's not many left to optimise timing with. Whether I lose some lemmings and just reach the required percentage at the end, or delay the crowd and exit when the requirement is met, the result is the same.
Time: 0-39 (90%)

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11: WAFD IV. You know the drill.
Time: 0-58 (100%)

12: A crazy combination of cursor-digging, inert triggers and the nuke glitch make for a lightning-fast solution by going directly through the steel.
Time: 0-10 (100%)

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16: Like Mayhem 3, this one was driven by a desire to solve the level in L++ with its faster timer. Digging a pit in the tunnel limits the spread of the crowd, and it doesn't even require messing with the release rate. RR fiddling could gain a couple of frames, but it's not worthwhile.
Time: 0-41 (100%)

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20: This level is extremely restrictive in terms of solution methods, so there aren't too many possibilities to try out. Heck, if the gap was just a little closer to the entrance, this solution wouldn't work either, and a sub-1-minute solution would likely be out of the question.
Time: 0-46 (100%)

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24: Frame advance makes this one trivial.
Time: 0-21 (100%)

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27: Identical to Mayhem 16, since I didn't make use of the free pit there.
Time: 0-41 (100%)

28: Building from the middle of the 4th step (from the entrance) gets the lemming into the ceiling without turning back. Because the basher's steel detection pixel is off the top of the screen, steel at the top of the level is useless and the basher just plows through. I save 2 seconds at the end of the wall by stopping the basher and using single strokes to clear the rest, and another 5 seconds by using up all the diggers instead of just one.
Time: 2-23 (100%)