Mass Effect is a series that blends a few different gaming genres together. Side-scrolling brawler isn't one of them, though, leaving room for this fan-made game.
It's called Mass Effect: Dark Corners of the Galaxy, and uses the OpenBOR engine (for fan-made brawlers) to bring the punchier side of Bioware's galaxy to life.
I'll admit, the character designs look more Dragon Age than Mass Effect (maces?), but it's still an impressive piece of work
You can grab a demo and try it for yourself at the link below.
MASS EFFECT: Dark Corners of the Galaxy (fan game — demo) [idealsoft, via IndieGames]