I don't know how much of this to believe, so i have to ask! Some sites that list achievments list the "Occult"-achievment as "finish mission 16". I have finished all 19 missions but still haven't unlocked Occult. I have even replayed mission 16 several times to see if the achievment would unlock, but nothing. Is the Occult-achievment unlocked by finishing mission 16 and if so, why haven't i got it?