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