According to ESRB, this game contains: Blood, Violence, Suggestive Themes
Parents should probably avoid this game, as it includes visuals and language that might not be appropriate for youngsters.
Motocross fans might want to give this a rent and see if the inclusion of some of the big names in the sport is enough to make a difference to them.
Fans of extreme sports games are also advised to rent rather than purchasing outright, as the seamless environment is pretty cool, but the DOA trick system will frustrate most.
For Deaf and Hard of Hearing gamers, pretty much everything is duplicated in sound and in text, so there's nothing to worry about there.