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