This game is really great, a fantastic play. I'd say that if you know you're kid is mature and can handle this level of violence (there is lots of blood and gore) and knows that the sexual exploitation of women is wrong (players can run both strip clubs and prostitution 'businesses') this game is A-OK. Judge your kid by their maturity to see if it's OK for them.
Seeing as I played the first Godfather game when it was first released in 2006, the violence was nothing new to me. The nudity and language didn't phase me that much either, but then again I have been exposed to mature content for years now. I can see how the game could be inappropriate for some, but it depends on the person.