I knew this from a long time ago! A lot of levels are missing water or fire in some levels. Here are all levels in Fun rating where water is missing in Dos/Windows version:
- Fun 4: Now use miners and climbers: No acid.
- Fun 6: A task for blockers and bombers: No lava.
- Fun 8: Not as complicated as it looks: No water.
- Fun 9: As long as you try your best: No acid.
- Fun 10: Smile if you love lemmings: No water.
- Fun 13: We all fall downm: No lava.
- Fun 16: Don't do anything too hasty: No lava.
- Fun 20: We are now at LEMCON ONE: No acid.
Also, for this level on the Atari ST version, there's blue water in pipes at the left of the level, it's the color of the acid when invisible (the acid is red and yellow under Dos, so I think it is why it is removed...)
- Fun 21: You Live and Lem: Some water aren't there.
- Fun 26: Nightmare on Lem street: No water.
- Fun 27: Let's be careful out there: No acid.
- Fun 28: If only they could fly: Oh, there's something interesting here, 2 steel blocks are added and some lava aren't there. In fact, these new steel blocks reduced the size of the lava lakes in both side of the level.
- Fun 30: Lock up your Lemmings: No lava.
- And so on for some levels in other ratings.
It isn't difficult to correct, just edit the levels.
I guess that the reason why some water weren't there is because of the memory. If a lot of objects are put in a level, some objects don't work, don't operate. I guess that you all already get this problem when an exit didn't work on CustLemm.