After two chartbusting efforts on Xbox, the enigmatic, genetically enhanced Spartan soldier known as Master Chief makes his highly anticipated Xbox 360 debut in Halo 3. The sci-fi shooter picks up where Halo 2 abruptly left off: The Covenant is continuing its plans to activate the Halo super-weapon and obliterate the galaxy; Earth is in utter disarray with only a few remnants of its armies intact; and the Flood grows stronger and more aggressive with each passing day. Your mission, as Master Chief, is to repel the Flood's advances, save Earth, and stop the Covenant -- no matter what the cost. Halo 3 offers a solo campaign, cooperative play, and multiplayer action via Xbox Live, system link, or split-screen display. The cinematic story line introduces new characters, weapons, and mission objectives, with the enemy AI offering distinct fighting styles, tactics, and even personalities, all while trying to rip your armored space suit into pieces. Familiar weapons such as the Needler have been upgraded and are joined with all-new armaments, including massive support weapons (such as a missile pod or turret) that switch the default perspective to a third-person view, chargeable lasers, and a gun that shoots out metal spikes. Players can also protect themselves with bubble shields, reach high places with portable gravity lifts, disrupt motion tracking with radar jammers, and more. Vehicles are also a big part of the action, with redesigned favorites and new class types entering the fray, such as the speedy but fragile Mongoose. The matchmaking service introduced in Halo 2 will once again bring similarly skilled Xbox Live players together, albeit with more customization options and a new streamlined interface. Players can still enter multiple lobbies, veto certain maps or game types, and so forth, but now they can instantly form parties with people they've just met for future matches, watch videos of completed games to learn techniques of the top Halo players, view detailed stats and rankings updated in real time, and squelch certain voices from being broadcast to their headsets.