According to ESRB, this game contains: Language, Suggestive Themes, Violence, Blood
Parents can feel relatively safe about their teens playing this game. Sure, it's violent, but it's in that relatively sanitized, completely accessible way that most people seem to find comforting, but I'm mildly unsettled by.
Germans may find this game unpleasant, what with the massive amount of violence directed at their countrymen that the game depicts, but given the subject matter, there's a good chance this game won't actually be legal in Germany, so it's only ex-Pats that have to be on the lookout.
Deaf and hard of hearing gamers will be a little troubled. There is subtitled text and onscreen indicators to tell them when they've been shot. But incidental sounds like enemy footsteps, so vital during stealth levels, will remain mysterious and unavailable.