Pros:
1. Character progression system seems to have hit the sweet spot between ME1's many redundancies and ME2's over-simplification. There's significant choices to be made in how you upgrade each power, which is nice.
2. Customizable weapons return. I don't know if there's any way to experiment with it in the demo, but at one point you can collect a pistol scope modification, so we at least know it won't be limited to minor things like damage/rate of fire upgrades.
3. Combat - while still not on a par with combat-centric games like Gears of War - is definitely faster and more fluid. Being able to dodge roll and vault cover without ducking behind it first is a big improvement. Removal of sprint fatigue is great, heavy melee hits really change how you approach close-proximity combat. If the latter portion of the demo is indicative of the whole game, then there'll be more options for combat too, as it presents opportunities to flank, suppress and drive back enemies.
4. HUD improvements! They're minor, but appreciated. I like how my allies' equipped power is displayed now, so I can see what they're going to do if I aim at an enemy and hit the ally command button. Segmented & always-displayed health bar is nice, and crucially, health seems not to regenerate on its own! Shields regenerate as normal, but you need to use the First Aid skill to recover your health in battle.
5. Grenades are awesome. Much better than ME1's silly frisbee grenades and definitely better than their absence in ME2.
6. My god, Kinect voice commands actually DO make the game better! I had planned to ignore this feature, but I tried it during my second play-through and it really gives combat a new feel. Using my own powers, commanding the use of all of my teammates's powers and switching weapons without pausing the game - without so much as pressing a button - was really great. I got over yelling at my TV pretty quickly, since I tend to do so anyway.
Cons:
1. Some of the animations are definitely a little unusual. While I find the faces look fine (mostly) while static, as soon as they start talking (wiggling their lips and chins while everything else remains stationary) it looks pretty bad.
2. Shepard still does that dumb thing where he runs around, gun shouldered, upper body rigid, whether there's anything to aim at or not. It looks pretty ridiculous, trotting down an empty corridor, furiously aiming at a menacing beige wall on the other end. I couldn't find any way to holster the weapon, but I'll retract this admittedly petty criticism if one exists.
3. The opening was not nearly as explosive and devastating as it needed to be. Indeed, it seemed to think itself a lot more dramatic than it actually was. After Mass Effect 2's incredible first 20 minutes, this was underwhelming.
4. Some of the dialogue (mostly in the opening) was awkward and strange, particularly Shepard's exchange with the young boy.
