Here is the full list of all 21 Occult achievements.
defeat the evil
kill with train
open 3 locked doors
big bang
collected 10 jewelry
kill mediums
sat in the closet for more than a minute
start a four-player game
killed the Spiderlady
mirror quest finished
25 window jumps
found the phone and answered the call
open lockers and drawers 50 times
first time stunned by a monster
throw a friend out of the cupboard 5 times
helped a friend get up
start a game together
caught 25 spiders
died from the fall
complete the game alone
5 minutes to stand by the car