I want to like this game...it just won't let me. Halo fans will most likely love it, casual fans may want to rent it.
I tried to dip my feet into the campaign. What I find with the Halo campaigns is that I don't really care at all about the characters and thus the campaign is very boring to me. I guess I just don't get into the whole Halo story and Master Chief is about as boring as a "hero" could be to me. What Halo doesn't do well for me is get me to realize what the reason is I am doing something from level to level. I played the campaign for about 3 hours and couldn't take it anymore.
People have always loved the multiplayer, and while there are some positive aspects to it, it's just not for me. My problem with the multiplayer is that I don't put the time into it that others might. This leads to me being overpowered on many games and thus being frustrated. I don't know if it is the leveling up system or not, but to me Halo rewards those who play A LOT. To some degree this is fair, and to some degrees it is not. Players who play a lot should reap some rewards, but those who pick a game up only occasionally, should not have to suffer completely. There needs to be more multiplayer balance and that is what frustrates me the most about Halo. After only a few weeks of not playing, I am so far behind those who have put days of gaming into it, that I now have no interest in playing.
I will say that the graphics are pretty good and if you can invest the time into the campaign and the multiplayer, you may enjoy this game. Halo fans will love it, but casual gamers may want to rent it first.