Having read the reviews from Gamespot and IGN after buying the game, I had a very nice surprise after playing it.
The game cleverly uses the screen for various tasks, including grenade launching, special weapon power-ups, and axe blows. Even for sprinting you can use the back of the console by double-tapping. Aiming and shooting is very smooth, even at the highest camera speed level.
An interesting feature of the game is that there are quite a few mini-bosses, and shooting and killing Chimera rarely becomes boring. There are two large boss fights; the last one is very difficult in the level I played ("difficult").
In sum, the campaign is relatively short, with a simple plot and a nice assortment of bad guys, including two major opponents.
The multiplayer is simple yet addictive. It's incredibly simple but fast-paced and very well devised. There are three modes and six maps. Games are typically short and intense. I must confess I am not very good at it, perhaps because initially your weapons are limited and do not have power-ups. Having reached platinum in the game, I plan to spent quite a few hours in the future in the multiplayer.
I beat the game in "difficult" level, and after that a "super-human" level was unlocked.
Overall, this is a very solid game which I think was under-appreciated by the reviewers of the main video game sites.