Most of the weapons from the first game return, although strangely the MA5B Assault Rifle (the default weapon in the first game) is not available. There is a single melee weapon known as the Covenant Sword, but the controls for it are the same as that for all the shooter weapons, making it difficult to direct. Also, for a new twist, you can hold two of the smaller guns at the same time and shoot double-fisted.
As for vehicles, the old favorites are back and joined by a few new, mostly Covenant wheeled monsters. Some improvements have been made to the AI so that the nonplayer characters can drive without running into too many obstacles while you man the turret. This improved AI also has enemies ducking for cover, and the banter from both the Marines and the bad guys has undergone massive improvements so that it no longer sounds quite so repetitive.