The Pros and Cons.
The Pros:
The Graphics are excellent, the gameplay in my opinion is well put out and multiplayer could keep you interested for quite some time. The Campaign mode itself has a pretty good story if you want to take breaks from Multiplayer or just want to actually play the game through and through. I'd say I'm about 1/8 of the way through it, don't actually know how long the hole game is, but I'm looking to be playing it for a week or so. It doesn't take too long to figure out how to play the game and the learning curve at that isn't that long at all.
The Cons:
It seems as though if your not quick, you can get killed pretty easily. The AI is pretty smart but at some times it seems as though they don't know where they are going. Playing the stealth part of the game doesn't seem to much possible considering the enemies are usually close together and start firing as soon as you are to say shoot one with a bow. There are points where you can get through it if you are quick with the bow, which is your main stealth weapon, but for most of the game you will be praying and spraying.
All and all I would say this is an excellent game if you are into the FPS genre, and even if you're not really into it, there is still the storyline which is real interesting and sort of Sci-Fi like. So I gave this game an 8.5.