The combat-centric theme of the next Mass Effect DLC pack was revealed by BioWare in a documentary included with the recent release of the Mass Effect Platinum Hits edition.
"We had something in Mass Effect 1 which we didn't have the time and we didn't think we would do well enough, which is a fight club arena," said principal lead designer Preston Watamaniuk in the video. "We wanted to be able to give people a much more combat-oriented, lighter-story kind of experience," said project director Casey Hudson. "You're going to go to kind of a casino, gaming, fight club space station."
The developers also dropped a few details on the anticipated Mass Effect sequel. "Any save game that you make from Mass Effect 1, you should be able to carry that same character into Mass Effect 2," noted Hudson.
Said Hudson of the anticipated sequel: "In the second game, you're actually going to go through a darker period where you're really looking for answers... there are a lot of twists and turns, and it's generally a much darker experience."
[SOURCE]
