My quick lackluster review, of 2 hours into the game.
Combat is great, even for a shooter.
The graphics are beautiful, though my Low Res, Non-HDTV has problems with text, which are way to small. However, this isn't the most stable of systems. They glitch at some locations, but it's only barely noticeable, but still noticeable.
The art design is very atmospheric, and does a wonderful job at conveying the designers vision of the sleek, contemporary/futuristic landscape of the universe. Unfortunately, I hate HALO, and this takes a bit of inspiration from that series. If I can block out the part of my mind for a little while longer, and let Mass Effect stand out on it's own, then I'm pretty sure that my final opinion on the art would be that it is wonderful. I will have to wait though, to see if the game sucks me in enough for that to happen. If it doesn't, then the art design would only be about 2 notches above moderately good.
The conversation system is everything they said to would be, but not as polished as they insisted. It has glitches, and seems to be too reliant on the writers ability to make excellent dialouge, and not enough for the designers to make one that focuses on character choices. You seem stuck into the role of about 5 different premade character personalities, rather than 1 you create yourself. The bouncing back and forth effect seen in KOTOR is present here. You still have to manage out the premade choices, instead of following your own path more. Still though, the cinematic ability of the system makes up for the outcome of the conversation, but not enough of PC development. It is still a new system, and will probably be much improved in Bioware's later titles.
The RPG character elements of the game are clunky as well. They have the possibility of depth, but the lack of any ability to experiment, and the very "left-brained" in character leveling, and way to "right-brained" approach to character combat and stats, makes the system frustrating. It is very deep though, but the problem is that the depth is under the surface, instead of visible, which has me worried about the outcome of Fallout 3, since Bethesda is taking the same approach. All in all, The system is something you grow into, but I would have much prefered something close to the system of KOTOR.
I haven't been completely immersed in the story, since I'm not very far into the game yet, but so far it seems too dry, with no emphasis on motivations of characters. This, though, is only temporary, and my opinion might change later.
And thats it.