dark cornes fits too good...
First it's dark, very dark designed. On an tv-set with "black matrix" or similar screen of another brand you can't play in daylight, because you can't see anything, that's not a joke! If you know Resident Evil 4 on the Cube (A very nice horror game!) first reduce most of the colors and 2nd add a little bit of SplinterCell for sneaking around the "fish-heads" ;-)
The game itself is very linear and the puzzles are not too hard, in my opinion. You always get clues to get farther in the game. Something new in a horror game is the fact, that you are unarmed at the beginning, and for a relatively long time, of the game and you have to get your arms by searching for yourself.
Different to "normal" FPS is that there is no HUD or even a cross-hair, just as if you look through the eyes of your own. Nice and new, but sometimes it's impossible to interact with the environment without faults. Locking up a door opens it, because you aren't able to get the lock right in your sight. Bad if you are in a hurry and try to escape... 2nd bad and definitely in your way is the fact that the person you are playing gets some nervous attacks and breakdowns when he sees too much disturbing things and often dies thereof! Hears noise, sees things that aren't present, or get's in the head of something unexplainable at the beginning and sees right through it eyes. Not very sharp but this is just good for some scary moments in the game.
The control of the character is not so well done, when you get between, a rock and a hard place, you will soon figure out what i mean.
And don't be afraid of bloody screens and painkillers...