Its great. I rented it, don't know if I'm gonna buy it yet though, I'll probably wait till its a greatest hits, or player's choice, whatever its called. The great part about the game is that it makes sense in real world terms. What I mean by that is your first instinct is usually correct. If you were actually in the situation the main character was in, what you would do in real life you can actually do in the game. Its fast paced, its action packed, it'll scare the bejesus out of you, and you will not be able to put the controller down.
The moment I knew I was going to like the game was one of the first cutscenes in the game. The main character sees a bunch of "enemies" coming to get him in a house. When I saw that I said "oh sh!t" the exact same time the main character did. It was beautiful.
Edit: Well, there was that, and there was also the first time I used the shotgun. That helped me like the game too. :lol