Oven-Ready Lemmings: Simple but nice level. The top route looks like it's going to work but actually it isn't.
Suds Law: can be trick if you don't see the builder turn around to send the second worker lemming.
Two's Company, Thirty's a Crowd: attached two solutions. Both spare a basher and save some more lemmings than required.
Pillar Pairs: Now I used all every non-permanent skill.
Blockers Go To Heaven: I think I backrouted it.
Crystal Cavern: attached two solutions. First one is just a slight tweak of my previous solution, and the second one is a good old ceiling route solution.
The Ultimate Quest, Take 3: attached two solutions. The second one looks intended
Using the bottom of the starting platform requires outside the box thinking and I like it.
Temple of Doom: It's trickier now. I used all the skills and managed to save few more.