If you haven't tried this game, then I suggest you do.
If you want a gritty, realistic (or as realistic as possible) shooter-type, along the lines of over-the-shoulder view perspective, ala Ghost Recon Advanced Warfighter, with the graphic intensity of the latest in games design, with interesting squad play and a gun with mounted chainsaw... then you've found it.
I bought it, as this game appeals to my tastes. It reminds me of the old Space Marines, and I love the general designs of the characters (with their bulky power armor), and the big weapons, and alien scum that needs to be purged from the face of all existence(!).
Not to mention it has a two player co-op mode, where you can play through the storyline (offline), whether it be split screen or LAN; and that's rare to have these days, save for Halo, as the majority of 360 games coming out these days require a link up of multiple 360's, which sucks balls.
As stated, graphics are intense, the gameplay is shiny and polished, and the realistic use of cover (lest you stand alone, ala Halo, and be blasted to bloody, little pieces) is a great addition to the genre.
Go.
Play.
Enjoy.
