In the demo, players step into the role of Commander Shepard and must escape from a Cerberus space station under siege. Players can jump ahead to a later mission where they must rescue Subject Zero, a hardened, dangerous criminal from a heavily guarded prison ship. Once they play the demo, players will be able to create a save and carry over their character along with the experience points, story decisions, achievements and weapons earned into the full version of the game – picking up right where they left off, on both PC and Xbox 360.

BioWare also announced today that players already in the game can download a new game add-on called “Overlord”, adding five new areas and two new achievements. Available June 15, the game add-on is available for 560 Microsoft points and on PC for 560 BioWare points. Also on June 15, BioWare is releasing a new premium theme based on Omega and new avatar items for Xbox Live will follow on June 17.