Common sense say "Not for kids" This is a BOXING game, you'd only buy it if you are used to a bit of violence, they don't exactly bleed much and don't really go over the top in any aspect. So, Common sense. Stop being stupid and putting people off games that aren't even that bloody, gory or even violent. The game is challenging, that is the only reason its not for kids.
Come on common sence you do this all the time. Everytime there's a M rated game you always say 18 and up like if the violence was a 4 and the sex was a 0 and the language was a 3 you would just say 18.
This game I believe shouldn't be marked as "not for kids". Yes, there is some blood but nothing more than bloody noses and lips. The fighting I don't believe is bad at all. Boxing is a sport, the violence (punching) is the way the sport is played. There is very little sexual content, nothing more than what you would see at the beach or a swimming pool (women in bikini's). Bad language like sh*t, d*mn, b*tch and hell is used very briefly during the story mode. At the main menu there is an option to turn off the explicit content.