Using GuyPerfect's idea, I have a similar method that saves 2 builders but uses more miners. I also used 2 worker lemmings to save time.
(in either case you can now update the list in that this level can be solved 100% without a glitch! (the previous method being freeing a falling/landing bomber glitch
))
-this method could be possibly be improved to save time and skills-
Skills used:
2 Climber
18 Builder (?)
2 Basher
8 Miner
2 Digger(?)
1- first use 2 builders to build up from the entrance area.
2- Here's where there are two ways to separate 1 or 2 (I used 2 to save time) worker lemmings.
-start bashing left and have another lemming mine the steps at the very top so a lemming could climb up later.
-OR let all the lemming come through the bashing tunnel and make a lemming a block at the end letting 2 through. (You can free the blocker later by digging and mining or bashing or building)
3-when 1 of your worker lemmings comes to the end of the steel hallway mine him at the end (just missing the steel)
4- he comes to the area where the weasels are, turns, and walks all the way around, down to the lower area. (see picture) Dig at the spot near the vertical column underneath so he and/or your other worker can climb back up.
5-if you have another worker, make him mine in the spot shown in the picture. (This is to delay the weasels later.) (If you're only using 1 worker you'll have to do this later). build at some point to stop him so he doesn't break through. Now we'll let him walk back and forth safely in the area for a while while the other works.
6- (Lem1 below) mine through the other thin column (you will probably need the 1 basher later)
7-build over the water (this takes 2)
8-build up to the shorter tall platform (this takes 2)
9-build up to the taller tall platform (this takes 2), then build twice again up to the ceiling where the balloon is to turn around.
10-let this lemming walk back the way he came and make him a climber so he climbs up the hole you made and back up to the top. When he gets to the right most wall (underneath where all the other lemmings are, mine into the ground so he can't climb up to a dangerous height
11-
While he is walking back, at any time when the first is walking back to the right and away from the weasel's area; have your other worker mine for exactly 1 and only 1 stroke into the wall holding the weasels in. Then immediately build to stop mining and pass by the weasels safely. You'll probably need two builders to pass the weasels.
12- the weasels will walk away and down into the tunnel you mined earlier. While they are doing that, have your worker mine down left into the steps your other worker build underneath. when he gets down build one near the ceiling to turn him around and he will follow the path the other just took. while walking to the right make him a climber to escape.
13-The weasels will come back to the area near the balloon and fall down the mine hole then into the area with the laser gate and trip it.
14-have your two worker lems build over the holes you've made (there should be two, then free the rest of the lemmings by either building over the gap you made at the beginning or freeing a blocker.
notes:
-usually for some reason, (this should be solved easily by timing in the beginning) the worker lemming at the top is always at the exact position relative to the weasels so that if you go through the wall he will come in contact with one of them immediately. So I had to delay him before beginning.
-having one worker saves skills but uses more time.
whew!