Those rings in space keep a-spinnin' as Bungie has revealed a new mode for upcoming Halo 3: ODST. Firefight mode will bring more than just the titular battles involving firearms, as it will allow up to four players to play co-operatively over Xbox Live or system link. These four stalwart ODST troopers will be tasked with dispatching wave after wave of attacking Covenant forces (think Horde mode ... with plasma grenades). Firefight mode will also include vehicles and, as an added twist, incorporate skull modifiers as you progress. And if your friends doubt the four Killtaculars in a row you just netted, you'll be able to point them toward the persistent leaderboards before you kick them out of your house and never talk to them again.