Good game but not what I was hoping for.
Now onto graphics, sound, etc.
The graphics in Halo 3 are great. Awesome lighting, shadows, and particle effects. The only thing that I have trouble getting around is that the whole game looks and feels kind of cartoonish.
The sounds are also great. The sound from guns sound sweet and the alien guns all have cool and unique sounds. On some levels and multiplayer games, there are explosions going off everywhere (grenade spam >.