Here is the full list of all 9 Crypt achievements.
I'm Sorry for your Loss
Greg
It's Possible. See? There's an Achievement Right Here for It.
Collect all three tomes in a single run.
Collect all four keys in a single run.
Fail to Beat the Game. Unlucky I guess...
Mr. Greg and his Brothers have Arrived.
Nice Work.
Complete the Game on Nightmare Difficulty.