Mainstream

Mainnsteam is a DLC pack for Mass Effect 3. It was released on all platforms on May 20th, 2012, and was free for the first week. It is free to anyone who has achievments in all three Mass Effect games, as long as they connect to EA or Orgigin. Otherwise, the DLC is 800 Microsoft or Bioware points, and $9.99 USD on Playstation network. Unlike previous DLC, it affects both Singleplayer and Multiplayer.

The DLC details the turian influenced but mixed species colony Mainstream, a large colony so far unaffected by the Reaper Invasion. Commander Shepard and the Normandy's crew visit th colony in order to regain full control of the ship, and help EDI battle a Reaper made virus, which is slowly scrambling her systems and rendering her ability to process information inadequate, and forcing her to become a liability.

The multiplayer section details in flashbacks, back to the age of Protheans. This multiplayer segment is accessible by choosing Flashback once multiplayer is selected, successfully adding another menu. In this version of multiplayer, the players fight as Protheans or Prothean conquered races, and one uplifted race. Unlike the original multiplayer, a larger story exists.