Halo has sold over ten million copies, and for the life of me I don't know why. It's got a terribly small selection of weapons, very little dialog, is obscenely linear, and includes the most annoying system ever used in a game; the infamous check-point save system. Which will give you Deja Vu and a headache from pulling your hair out at the same time. As far as content, nothing bad in it at all. The marines use some salty launguage a couple of times, but not nearly enough to be an issue. The violence really is not too bad by today's standards. Really, for the life of me I can't see how it got rated "M". Still, in both gameplay and content, Halo is over-rated.