A great game, but not the best FPS like most say...
Halo plays just like every other first person shooter: you shoot things. The levels designs are nice and big, which is something I do like. The vehicles are a nice addition to the gameplay as well. However, this single player campaign is really short, and the last half is tedious (the Library, ugh! and lots of backtracking afterwards). The game is more enjoyable co-op/multiplayer.
Graphics:
Really good. Some of the best I have seen on the Xbox.
Sound:
Good SFX, alright music, and okay voice acting.
Value:
The game has lots of replay if you play multiplayer. The single player campaign is quick run through (7 hours, roughly) and that's it. You probably won't play it again unless you want to try a harder difficulty.
Overall:
A really good shooter, but I have played better. Definately worth checking out though.