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