Im going to start again probably this weekend.
Since the screen is so dark, I have to play it with the lights off (of course) and in order to hear the ambient sounds, with the volume at a louder setting than usual (of course). This does not make for a pretty scene when the stuff jumps out.
I've read of people playing for 11-20 hours straight, but unfortunately since I can only handle 15 minutes intervals, this game may last me a while...