1. Contextual leap/crouch mechanics. Makes gameplay smooth. 2 buttons does pretty much all your parkour needs.
3. Parkour in 1st person. It really feels like you're doing the moves, and movement feels fresh and exciting. It feels like Prince of Persia.
4. Emphasis on running. Certainly mowing down enemies belong in an FPS. ME isn't an FPS (thank goodness).
1. Anime-style cutscenes. It's ok. I don't really mind it as much as other people do.
1. Combat. Clunky, and hard to time right. I know it's a common complaint, but it is a problem that I hope to see fixed in ME2.
2. Parkour in 1st person. It's just difficult to position things right, and sometimes you don't know where you should be going because the red object is behind you or something.
3. Gun play. Sorry, but no auto targeting, nor any way of aiming the gun better than using your right analog stick is a bit painful.
4. The right analog stick. Goldeneye, the only FPS I've played and gotten comfortable with controls with.