8-10 Walk the Plank or Join the Crew?
>>>[with exceptions] - that is, I didn't actually use just 1 lemming, I used 2, But I did use only 1 from each hatch. I'm 50-70% certain only 1 lemming isn't possible.* Thanks again to Pirohiko for some help.
I Don't really care if the original poster wants to add this to the list or not, I just feel like mentioning the levels like this that come close or have exceptions.
Any other levels like this I will not bold the title to give an indication in case I forget to mention it
-set lower RR to 1. The first lem here will be the main worker. Make a blocker on the top [he's the only one you use on the top and that's the only skill you absolutely need to use on him] Make sure to allow plenty of room between the wall and blocker.
-on the bottom, make him build twice to the platform. Two lemmings will die. When he turns around make him climb/floater.
-Let him climb over the one way wall, on the other side build over the lava.
-Near the teleporter, dig or mine and bash to remove the top layer of ground [make sure no lems can enter the teleporter on the right side, they need to enter from the left.] Make him built to stop somewhere on the left of it.
-Let him turn around and build over the lava again to seal the gap. Bash through the one way wall.
-When he comes around to the teleporter again build up to it {on the left}. They will come out up top, build and bash through that 1-way-wall. When he's bashing and almost done, at the ledge, you can build one brick to make him turn around quicker later (this is not necessary since you have a ridiculous amount of time on this level).
-As everybody gets caught in the top area, have him make a builder wall to separate everyone from the blocker. Make sure to isolate him on the right; you can use the hatch to turn him around.
-Build over the blocker, let him go past the speed up pad and through the door. Use bashers or builders to stall him if he isn't timed right to get through. The laser on the other side frees the weasel and keeps the door open.
-Use a builder to turn him around. When he comes back, build over the blocker again then destroy the builder wall. They are free to go to the exit.
notes: in the pic, I instead reset the blocker and he went to the exit.
*The problem is that if you leave the top lemmings alone [setting RR at 1] they will get knocked off from the opening/closing door. Once you turn on the speed up pad (From below) 1 will eventually get past but he then sets lose the weasel; who will trigger the laser that shuts the door closing in the lower lemmings. If you go for saving the top quicker by having the worker climb the one way wall and turn on the speed up pad; the weasel is freed too soon and you can't get the lower lemmings out quick enough. If you try to set a trap for the weasel for him to avoid the laser there too many lemmings on top die. [I haven't found a very quick way to accomplish all of those things at once, but maybe somebody else can.]