WillLem's Investigation!Mayhem 28
Mind The Step... - Unconfirmed. @Ste Woz Ere - Can you remember which two pillars it was, and whether you need to build a little bit from them or whether you can just walk off?
Wicked 2
Inroducing SUPERLEMMING - Unconfirmed. @Ste Woz Ere - Can you remember the exact location, and how to reach it? A couple of people on
this website claim that the exit glitch is near the beginning, but unfortunately the images on the site don't load so it's difficult to see exactly where. I did a bit of trial and error to see if I could find it but didn't manage to.
Wicked 3
This Corrosion - Confirmed. From the beginning of the level, just let the lemmings walk. They fall to the bottom of the screen, die, and then exit via the glitch!
Wicked 5
Chill Out - Confirmed. Send a worker to the left and float down. Have them bash through the snowy pillar beneath the exit, then build across to the stalagmite. Bash through it and then walk off to the left. The lem will die and then exit (as will the following lems!)
Havoc 18
Lemmings In A Situation - Confirmed. From the beginning, have one lemming climb over the steel block to the right and float down. At the very end of the brick section, dig and then build. The lemming will drop into the exit glitch. I tried completing the level this way and it seems that only Floaters can exit... this may have something to do with the positioning of the Builder though.
ONML Multiplayer 5
Showdown - Confirmed, but it's not an Exit glitch. If you dig directly down, there's a spot where the Burner animation plays as the lemmings fall offscreen, and there's another spot to the left of that where the Drowner animation plays. I cleared a bunch of terrain to make these easier to see:
Burner
Drowner (it happens very low but it's obvious it's the Drowner from the way it moves across the bottom of the screen)
I'll continue to investigate these when I have a bit more time. I find it highly likely that there are even more to discover as well!