In Mass Effect 3, an ancient alien race known only as “Reapers”, has launched an all-out invasion of the galaxy, leaving nothing but a trail of destruction in their wake. Earth has been taken, the galaxy is on the verge of total annihilation, and you are the only one who can stop them. The price of failure is extinction. You, as Commander Shepard, must lead the counter assault to take it back. Only you can determine how events will play out, which planets you will save from annihilation and which alliances you will form or abandon as you rally the forces of the galaxy to eliminate the Reaper threat once and for all.

At its Summer Showcase event Electronic Arts revealed the Mass Effect 3 Leviathan DLC

Something lurks in the dark corners of space, something powerful enough to kill a Reaper. Shepard must discover the most closely guarded secret in the galaxy before the Reapers silence it forever. Discover more about the origins of the Reapers as you race across the galaxy to find the Leviathan. Unravel the dark history of the Reaper Race before it is too late... Taking place during the events of Mass Effect 3, players will be thrust into the darkest corners of space where they will hunt a mysterious being rumored to be powerful enough to destroy a Reaper. As they race against time, they will begin to unravel the secret of the Leviathan. Explore uncharted systems and new areas on the Citadel, interact with brand new characters, unlock the AT-12 Raider shotgun and M-55 Argus Assault Rifle and discover more about the mysterious history of the Reapers.

Mass Effect 3 Leviathan DLC will be available later this summer for $10/800 Microsoft Points.

In addition Electronic Arts will also release the single player Firefight Pack on August 7, 2012 ($2/160 Microsoft Points), which includes two powerful new weapons and five bonus weapons.

Mass Effect 3 on the Xbox 360 includes support of Kinect, allowing players to immerse themselves into the Mass Effect universe even further through new voice recognition technology.