Howdy!
I've taken a looksie into what might be causing some players to experience the achievements not unlocking and I believe I may have figured it out.
Specifically-speaking, the achiemevent for the bad end may have not been triggering if you did not have all 4 cards and talked to the devil a 2nd time. If you did have the cards and lost the hand of poker then the bad ending achievement unlocked that way. It was supposed to unlock under both circumstances but I believe it only happened under one of them.
So if you get to the end without all four aces and lose BEFORE playing the devil at poker (i.e. you don't get the chance to play poker) and this achievement STILL doesn't pop up then I don't know what else it could be.
Tarnation!
Merry Christmas!
-Del_Duio