Single Player, Xbox LIVE Multiplayer 2-16, Local Multiplayer 1-2, System Link 2-16, 5.1 Surround Sound, HD (High Definition). Buy the full version of Undertow and join up to 16 players in underwater battles for the survival of humanity! Non-stop action ensues through four multiplayer modes and robust 15-level single-player and co-op campaigns, featuring stunning graphics and special effects. Hours of explosive gaming action await you in Undertow's immersive underwater environments with depth charges, missiles, and vehicles. There are no refunds for this item. For more information, see www.xbox.com/Live/accounts.