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