Remember the suicidal lemmings? I remember playing this on a school computer in 1993. Oh my.

This one has all the levels, and is written entirely in Javascript. If you haven’t played Lemmings before, it involves guiding a bunch of suicidal lemmings to their final destination through traps of fire, lava, water, heights, etc by giving them the tools to climb, build ladders, float Mary Poppins style, and self-destruct. Requires logic, and only at times fine motor skills. This version runs just like the old one, allowing you to choose between four difficulty levels, then giving you a password as you finish each level so you can go back and play more whenever you want.

Free, and AD-free. (Can’t promise the latter one forever; I’m not hosting it.)