Overall, I really enjoyed this game. I have been playing the Halo games for several years now and out of all them, this is installment is definitely the mildest.
Message: Not much here, but as the main protagonist Master Chief (John 117), you shoot and kill a ton of alien enemies. In multiplayer, you kill other people just like yourself.
Role Model: Master Chief spends the whole game trying to protect his friend and AI helper that was assigned to him in the first game, as she also protects him. This could possibly spark thoughts of what true friendship is like.
Violence: As far as bodily fluids and parts go, it doesn't get worse than blood splatters. Note that you can sneak up behind enemies and assassinate them (e.i. break their back, stab their head, snap their neck, etc.) though no bones can be seen, it is obviously violent. Again, know that in the single player mode you are fighting and killing aliens to protect your friends and the human race.
Sex: Though there are no sexual acts or remarks, Master Chief's AI companion is quite obviously female. It is about like Mystique from the X-Men movies. No nudity, but basically wearing a skin tight suit through the entirety of the story. There are a few shots than pan from the base of her legs up to her head and show a clear shot of her behind (clothed, but nontheless, skimpy).
Language: The profanity is extremely mild in this game. Two or three "hell" and one use of "b****". A few uses of taking the Lord's name in vain.
Consumerism: If this is your first Halo game, you most likely want to play the others as well, or even buy a book or two.
Drinking, Drugs, Smoking: None that I recall. Previous games had a Sergeant Johnson that sure liked his Cigars, but he is not in Halo 4.
Safety and Privacy: Just like pretty much any other game you play online, there are people who will make inappropriate comments. They can however be muted or reported.
Well, I tried to give an a honest review to the best of my ability! Though there is not much educational value in this game, it is very fun and could provide time for you and your child to play and work together as a team. Keep in mind, it is an M Rated game (for ages 17+), but i still think this is because of online play or possibly just to keep players who enjoyed previous games and might look down upon a T Rating? It sounds dumb, but i have seen it happen before. Anywho, I hope this review helps! Enjoy the Halo franchise! God bless.