I don't see any need to have 100 lemmings in a level. Anyway, I've quickly gone through the new pack.
1: Nice simple level. Very interesting possibility of a solution going via the left side of the map.
2: Too easy? This could go well at the start of the game, I guess.
3: I like the decoration. Check your trigger areas
4: Again, check your triggers. A little heavy on the flamethrowers I think.
5: I found a backroute that saves 9
with a miner to spare, and without using the floaters, [edit: and two spare builders]. This can probably be fixed though.
6: I think this would be better if you removed the fake steel and had regular terrain in its place.
7: Fairly simple. I like it.
8: I don't like this one. Hidden exits have been done to death.
9: Interesting. The apparently obvious "outside route" doesn't work, and the actual solution doesn't reveal itself straight away.
10: Could use some decoration.
Re: trigger areas: You can only have 16 working triggers in one level due to limitations of the original game. Any objects placed beyond this will not have triggers, which leads to (among other things) lemmings falling through water instead of drowning. This is easy to fix - select all objects that don't need triggers (water that can't be reached, trapdoors, top part of exits), then cut and paste.
And my pack is now up to 9 levels. Look out
