This is one game that makes superb use of lower lighting settings. Try it.
The game is full of interesting and challenging logic and physics puzzles. Some of the puzzles can be really out of sight and if you need a walkthrough I recommend mdav2's one, I used it.
As far as scariness goes, I get scared fairly easily and found this game only to have a couple of sections that were truly frightening. But don't let that put you off this game.
Overall, this is an interesting game that sucks you in, has refreshing game play (the way you interact with the environment) some good scares, good tension and mood throughout and great puzzles.
What I didn't like about the game is that scourging for supplies can get tedious very quickly. So many places to look, cupboards to open, rooms to go in.