My dh has played Halo for several years and ds (now 14) got into it a couple years ago. (He's getting #4 for Christmas). I am okay with my kid playing it but after reading this
Parents need to know that Halo 4 is a sci-fi-themed first-person shooter in which players take on the role of an enhanced super-soldier to kill hundreds of alien enemies in story mode and potentially thousands of human avatars in online matches. Unlike many other first-person shooters, there's no foul language or gore, but there is plenty of blood -- aliens bleed yellow and blue, humans bleed red -- plus new cinematic animations that make hand-to-hand combat kills appear more dramatic. This version of Halo ups the ante in terms of violence as players can now watch Master Chief violently beating his opponents to death. Parents should be aware, too, that this game supports open online communication with strangers.
I probably would be iffy about getting it for a 10 year old. I'm a little disappointed that the violence has been amped up. I thought the other three were similarish to Star Wars Battlefront and I don't remember them having blood.