I'm thinking about buying this game for my nephew, since he's been asking for it for a while now, but he's only 13 years old and I've heard this game has a lot of violence and gore. Someone told me that you can "turn off" the gore and mature language in the game if you want to... Is this true? If not, would people who have played this game before say it's too violent/mature for a 13 year old?