According to ESRB, this game contains: Animated Blood, Violence
The only thing parents have to worry about are some scary looking monster designs, and the fact that they will die. Beyond that the game is as offensive as The Wizard Of Oz or a Salvador Dali painting.
Shooter fans can't afford to miss out on this one, though it's more likely that most of them have already bought this game. It's classic gameplay with a slight 3D twist that keeps thing deceptively complex. The game may be too difficult for some gamers, but eventually with enough time all the secrets would be unlocked.
Deaf and Hard of Hearing gamers won't have anything to worry about. The language isn't even in English, and is translated with subtitles.