Halo 3 is a fantastic game. But it has problems. Scary problems.
I have issues with the graphics. Not that there's anything inherently wrong with them - in fact they're some of the most lush and beautiful video game environments that I've ever seen, and that's including a lot of games with pre-rendered graphics. The problem is, they look a lot like the graphics from Halo 2, and repeat a lot. I know that I'm only playing it on a standard resolution television, but still if you've seen one burned-out futuristic African highway, you've seen them all, it seems. I miss seeing Covenant environments, with their purples and blues and tripped-out glowing things. Halo 3 has some varied environs, but they don't look significantly sci-fi for my tastes (and my tastes don't include walking around a level that looks like the inside of someone's colon - don't ask, just play the game). Some characters animate really weirdly (I'm looking your way Lord Hood), and some just not enough (Master Chief does a lot of standing around in cutscenes in this game - doesn't the guy ever cross his arms or anything?).
Multiplayer levels are a good mix of some of the best and some of the worst parts of past Halo games. They changed Battle Creek to Valhalla, but also removed all traces of teleporters and replaced them with jump pads (which in itself is a mixed bag), but I was tired of Halo's multiplayer deathmatch way back in the first game, and I can go without getting my ass handed to me by some stupid punk kid in Debuke, thank you very much. I like that you can customize your character's look beyond color (finally), but there isn't much variety there either, and you have to earn what you get which is novel but difficult when you suck as much as I do.
Control is the scariest thing. Because MS took away the black and white buttons and (thankfully) replaced them with the left and right bumpers, Bungie for some inexplicable reason decided to switch your weapon reload/pickup button to the "RB." I can sort of understand why, as it is easier to push (in theory) than the "X" button, but I've been playing it with the "X" button for almost six years now, only to have them change it on me and not let me change it back. What's more, "X" doesn't do something passive such as turn the flashlight on and off anymore - it acts as a deployable weapon now, such as a bubble shield, a health regenerator, etc. The first time you hit it to reload your weapon is annoying. The fifth time you accidentally use it is a metaphor-inducing rage, and if you're pinned down and have the blue shield-draining thing equipped (sue me that I can't remember the name) prepare for some controller-chucking goodness (all right, I'll come clean - even though I have a reputation for this it has not happened with my 360 controllers... yet).
The Flood are worse than ever. The scariest thing about them anymore is the fact that you know you'll be putting in about an hour more of playtime because even after you've emptied all of your ammo you still won't be able to take them out. And now they can climb walls and shoot you with spines, so any hope you had of cover is gone. Using the new flamethrower is just pointless, because the Flood'll just run up to you and burn you with their flaming bodies. You can't even carry as many grenades as you used to, to use against them. At best you'll probably start the flood level with two stickies and two pineapples, and maybe one spiker grenade. If you're really lucky, you'll find the incendiary grenades, but they're so rare (plus you can only carry two) and nearly useless why even bother? The flood aren't fun to play against because they're difficult for all of the wrong reasons.
At least they've fixed some of the more irritating aspects of Halo 2. The Brutes aren't the insanely stupid charging gorillas that they were in the last game, but they're still not as fun to fight as the elites (there I said it) You can finally destroy the Phantom spaceships and the Scarabs, though you still can't use them in multiplayer. The textures don't pop in and out anymore, which is sweet, and they FINALLY added online, four-player co-op (took 'em long enough). The "Legendary" difficulty level isn't nearly as unfair (One person dies, you both lose. Remember that?) as it used to be, but it's still a respectable challenge. Your troops are marginally smarter than they used to be too - I have yet to have my own soldiers run me over with the Warthog, something that was a consistent problem in Halo 2. They are, however, still useless in a firefight.
I don't know. I know it's a decent game, but I'm bored with it already and I haven't even owned it a month yet. If it weren't for the prospect of playing it online with my friends who also own the game I wouldn't be playing it at all.