 As a result, each version of the game features different user interfaces and controls.Like its predecessor, "Mass Effect 2" was built using Epic Games' Unreal Engine 3 in conjunction with a framework that BioWare specifically developed for the "Mass Effect" games.As most of these "Mass Effect" technologies were already developed in the first game, the development team focused on adding a lot of new content and perfecting new features rather than creating them from scratch.