When it came time to create a sequel to its critically acclaimed bestseller, Mass Effect, Electronic Arts-owned developer BioWare focused on improving Epic Games' Unreal Engine 3 base technology to create a more immersive sci-fi role-playing action game experience. The game has already sold over two million copies worldwide, solidifying itself as the first big game of 2010. Over 150 people at BioWare worked on the new game, which is the latest blockbuster from the acclaimed developer. Having worked with UE3 on the first game, Casey Hudson, lead producer on Mass Effect 2, said his team has been able to push every aspect of the new game forward from both a technology and gameplay perspective.