I heard a lot about this game. Too afraid to play it cause I'm not a fan of horror. Just the video sent my heart into patters.
The main mechanics of the game (read up on it) is that you are in a castle and you have these creatures that come after you. You keep going through the castle to try to get to a certain place and obviously have amnesia. You have no weapons so when you run across one of these creatures you have to run away and hide or else they kill you. You can block the door and stuff and after a while the creatures will go away when they get bored. However the longer you're in the dark the more your 'sanity' disappears. When it runs out you faint and if the monsters find you, game over. However if you do survive and wake up then you're full sanity again.