Great game, but the story, characters, and conversations, make it ground-breaking.
I loved the chartacters. The story, which for some reason so many reviews put down, I thought was great, especially the individual side stories.
I played on win7, 64bit, and I experienced no bugs. Ok, like twice I got stuck in a wall, but for a huge rpg type game with so much ground to cover, thats nothing to complain about.
The graphics aren't given enough credit. One, they look great style wise. Two, although they aren't the MOST tech advanced, I didn't see ONE thing pop in. To me pop in's are such an immersion killer. Games like Fallout 3 have so much it and it really takes away from the experience, so a game like ME2 should be given that much more credit for not having any. And it ran very smooth on my machine no matter how much was happening on the screen.
Sound, just like the first game, has a wonderful laserbeam/futuristic feel to both the music and sound effects.
You can't help but want to replay this game with all the ways the story can go based on your decisions.
Finally, their two sides to the gameplay. The action side and the rpg side. The action, like so many others have said, is way better than the first game. To me, it plays just as well as any other 3rd person shooter, but with so many tech powers and biotic powers along with the standard weapons, I can't help but feel like gears and uncharted don't quite hold up.
On the rpg side, so many people are saying this is a watered-down rpg. Well, first, even if it is, it offers so much else, who cares. Second, I disagree anyway. The story, and conversations count towards being an rpg. That alone is enough to warrant being an actual rpg. The leveling and loot part I think is genious. You still have tons of upgrades, which, (small spoiler) does play into the story. There is also very little grinding, which for purests might be negative, but to me I don't care about killing the same enemy in the same environment over and over to get that sword I want.
The one negative, which wasn't all THAT bad, was the mining. I didn't mind it and when I wasn't ready to start a whole new mission I would just kill time doing it. The way you had to move the mouse around so much made my hand cramp, if only they tweaked the way you did it in some small way it would have been more fun.
So overall, an awesome game and I CAN'T wait to play the third one.