Impossible badge is just impossible. I really tried to. Got 5 achievements for all easy, medium, hard and 1st and 2nd professional levels, but the 3rd level is just undoable. :-(
if you are struggling to know the elevator code, read Mr. Gilbert's thoughts... you will discover that the lenght of the words corresponds to the numbers.... anyway, it's 3544 5426
Yeah, that one's tricky -- here's a helpful video from PsyMarth: https://youtu.be/sZUf_8m4ksg