what @xWALLAFFLIZHx said. very nice puzzle game. I do have a few nit-pick improvement suggestions (I always try to leave some amount). the two slimes with two different controls should have slightly different looks/colour schemes. it's a minor thing, but the extra key press to see which slime is which is kind of annoying. your platforming could also use a bit of improvement, try upping the player just enough so that the platform is not just barely at the height of their maximum jump, give them a few more pixels of leeway.
But other than that. great job, it was a pleasure to play it.