I actually just picked this game up from Steam about a week ago. It's awesome. I love the story, the sci-fi setting, the characters, and the action is pretty good. The graphics are pretty decent -- the character models are impressive, though some of the landscape gfx & design is pretty boring/repetitive. The voice acting is fantastic as well -- though sometimes I swear the dialogue option I picked wasn't nearly as snotty or angry as Shepard makes it sound. I also feel like it's too clearly a port from a console at times -- I shouldn't have to rotate the camera to tell my squadmates where to go, I should be able to just click it with the mouse.
Anyway, it gets an A+ from me. My biggest complaint is that it's not a game that lends itself to playing in 1-2 hour chunks, which is generally all I have time for. I have trouble turning it off.
Oh, and it doesn't recognize my 5.1 surround, and I haven't figured out how to fix that yet. :sad: