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