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