Red Sand is a fan film taking place long before the events of the first Mass Effect game.
The Mill's Work on Mass Effect 3 Trailer
See how The Mill created the live action trailer for Mass Effect 3.
Making of Mass Effect 3 CG Trailer by Digic Pictures
See how Digic Pictures created the awesome Mass Effect 3 CG trailer in this huge making of article.
Brian Sum's Concept Art for Mass Effect 3
Check out this gallery of beautiful concept art that Brian Sum has created for Mass Effect 3. (Beware spoilers)