Hands down one of the best games you will ever play!
The only downsides of the game are high requirements to enjoy the graphics at the max, singleplayer campaign ends (believe me, you don't want it to end), and the cliffhanger. As well as the multiplayer I'm not a fan of Counter-Strike so Power Struggle is a bit weird in my taste. However, I should be able to acquire it.
Overall, EVERYONE should play this game. Including the people who played Halo 3. Believe me, you will be blown away from it.
RECAP:
Pros: Immense gameplay; A storyline that is unforgettable; Beautiful graphics; Accurate Physics; Great interaction between characters; environment is great; Technically Proefficient (high requirements, yes, but it will blow away Halo 3 graphics and physics by 1000x, at least)
Cons: Multiplayer needs some tuning (dieu merci for patches); singleplayer campaign ends; and the cliffhanger.