Very good game, despite not very favorable reviews.
The game is very well made, surprisingly bug-free, and I don't really have much negative to say about it. It's got some stealth elements, some close-quarters combat, as well as some sniping. Interesting and very well said story. The game actually starts from the end, and then it tells the story how you got to that point, and then you continue from that point to the grand finale.
The controls are very solid, although weapon aiming is a bit wobbly. Graphics aren't spectacular, but not bad either. The quality is pretty good, and the games fares very well on the PS3.
I found camera a bit awkward at times, and it suffers from all the same problems most other third person games suffer, where it starts swinging uncontrollably, to the point where you can't really figure out what's going on. But unlike many other games, here that doesn't happen as often, and usually it's not as annoying as with others.
Overall, I think it is a very good game, and deserves to be played - if not bought, then definitely rented.