Join your friends in the all-out galactic war to take Earth back. The universe of Mass Effect expands with the addition of new co-op multiplayer missions. Players can choose from a variety of classes and races, form an elite Special Forces squad, and combine their weapons, powers and abilities to devastating effect as they fight together to liberate key territories from enemy control. Success in multi-player will have a direct impact on the outcome of the single player campaign. The Reapers have invaded and it will take everything to achieve ultimate victory against the greatest threat mankind – and the entire galaxy – has ever faced.