According to ESRB, this game contains: Animated Blood, Violence
Parents might be put off by the game's Teen rating, but there's really nothing all that troublesome in this game. Yes, there's fighting and some spilled blood, but it's not gory or gratuitous. Once again, the ESRB errs on the side of caution in giving out a rating.
Hardcore Rare fans will probably enjoy this more than the average gamer. It has all the hallmarks of a Rare title from the late N64 era—a bazillion collectables, cute characters (almost too cute) and a whimsical tone. That being said, it's not really any different from about ten other Rare titles. It's pretty, but the gameplay isn't particularly deep or fun.
Casual gamers will like the short length and the fact that Kameo is a game that can be picked up, played for a brief spell, then put down again. The control scheme might be a turn off, though.
Deaf and Hard of Hearing gamers will want to note that there are no subtitles during the cutscenes, nor could I find a way to turn them on in the options menu.