While reading the "What parents need to know" (I am currently trying to find a good reviewing site for games and movies I have not played) section of the review on Halo 3 it struck me that Marc was very wrong on a few points, and this may cause kids to miss out. First, Marc said: "Throughout the game, players shoot aliens AND HUMANS. You DO NOT shoot humans* in the campaign. It is possible, but if you do the marines attack you, as you are not supposed to attack them.
...and they'll see vivid images with blood. While playing campaign on Halo, if you shoot an alien, there is blood. Blue/Green blood, and that actually doesn't just pour out after you finish shooting. Also, there is zero dismembering/actual damage to dead bodies.
And know that when the Halo games are played online, players can communicate -- and curse -- via headsets. Depending on your gamer zone on xbox live, there is generally very little swearing. But, if you so wish you may mute players (only to yourself) in games, or simply plug in a headset and turn the speech volume off.
*Actually, in multiplayer, you do by default play as a human (albeit, a human in a suit that you only know is a human, there is no face, just metal) but if you so wish you can turn into one of the aliens (Sangheili, or Elites to be exact, the Arbiter is an example of this species, they have defected to humanities side) and fight that way.
For overprotective parents who fear xbox live like a dangerous animal, you do not have to play on xbox live to play multiplayer, or the game at all. Also, as long as your child does not act stupid, no one will ever be able to access their real name, location, phone number, email address (phone number and email are needed to register for xbox live, but are not shown to the public) or even what they sound like.
If you seriously look at the characters of Halo 3, you will find numerous good role models. Even John 117, Master Chief Petty officer, the soldier whose face is never shown, is extremely dedicated to the service of humanity. He is courteous, and many times goes out of his way and puts himself in danger to rescue his friends, in particular Sergeant Johnson. Parents, almost every concern you have about Halo 3 will be dispelled upon actually investigating by playing the game and reading about it yourself. If it weren't for a very few uses of b***ard and b**ch Halo 3 would be rated teen.