I hated a lot of the interiors. You feel far too confined, if its a huge city, why can't you experience it? Why is everything within a hundred meter radius? Jumping in a vechile and bursting through a city in a few seconds to reach another spot would have been far more 'immersive'. The outdoor areas look superb, even if you have to drive a predetermined route.
The combat is far too sterile. No weapons have a kick in them and the biotic powers feel the same. There isn't much interaction with the environment. I would've liked to have to seen glass shatter, chairs break, to have the world react more, but alas.
The story development is disjointed, very jumpy and not much point to it. I would've dug the B-movie script if they had gone balls out with it like Far Cry, but instead it takes itself far too seriously. You can't be the badass you thought you could, either. I do laugh when Shepard pulls the gun out, but that only happens on a few occasions.
The characters are the worst I've seen in a Bioware game (haven't played Jade Empire btw). There is no substance to them, you hardly ever talk to them and they hardly ever interact with each other. WEAK! Wrex has a few good lines though, he's the only character I liked.
The music is very good and Defjam describes it well. Its a bit System Shock 2. My complaint is that they use music far too little. Why do I spend most of the time with no music? Going overboard is common in games, but going under is strange, especially when you've got such a solid soundtrack.
I thought the game would have been huge. A big world to explore, lots of sidequests etc. But no. I have to admit I was really, really surprised at how linear it was! There are barely any sidequests, unless you count landing on random planets and stealing crashed probe parts from monkeys (actual quest!) sidequests. There are some better ones, but I dunno... The game just feels shallow.