According to ESRB, this game contains: Animated Blood, Violence
Parents should know the game is 100% gunplay. It's cartoony and not very serious, but a few of the animations are a bit on the gruesome side and the blood is red. Still, it's had to get concerned over such stuff when it's so light, bright and cheery. There is no questionable language or sexual content.
Old-School fans or people looking for a serious challenge will be thrilled. Fast fingers and faster reflexes are needed for this crazy-hard game, but it's an absolute blast. For everyone who moans that "they just don't make 'em like they used to," here you go.
3D junkies, casual gamers, and anyone with a low tolerance for frustration, go elsewhere.
Deaf and Hard of Hearing gamers will have no problems since there's no dialogue in the game and there aren't any significant audio cues.