IGN gives us a look at Crysis Warhead. Over all they give it a 9.4. Here is some of what they had to say.
Crysis Warhead is the videogame equivalent of a summer action movie, and while it's more action-heavy than its highly acclaimed predecessor, it still retains its brains. Like Crysis, Warhead is a sandbox shooter that gives you large amounts of freedom as to how you approach each tactical situation. And there are plenty of tactical situations, because Warhead seems aimed at those who felt that Crysis was a bit too slow-paced and cerebral at times. But while it doesn't quite match the over-the-top insanity of a Call of Duty game, Warhead does prove that Crytek can deliver an intense action game.