According to ESRB, this game contains: Comic Mischief, Suggestive Themes
Parents have little to worry about, unless they feel that their child is at risk for extreme sports overexposure.
Players in general should steer clear of this game unless they're complete jet ski maniacs. There are both better racing games and better games that involve pulling off tricks. Jet X20 does neither well, and cannot provide an enjoyable synergy between the two.
Fans of racing games should sit down and think about what they're looking for in a game. If they truly feel that they are interested in seeing a more varied, less cohesive experience, a rental may be in order.
Hearing-impaired gamers shouldn't have qualms about playing this game. Although there are some audio cues used, they are all made redundant by visual activity, with the added bonus of not having to deal with the insipid catch phrases being spewed over the waterways.