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