Aside from the combat, which has been greatly improved (aside from the over-burdened spacebar), I've got to say that I'm extremely disapointed. The intro just feels very weak.
Who is James Vega, and why is he chummy with Shepard when we've never met him before?
Why aren't I allowed to choose Shepard's dialogue?
Why is Anderson on Earth?
What happened in Shepard's trial? Why has Shepard's trial been skipped for that matter? That would have been such an engaging scene, not to mention an excellent opportunity for some needed exposition.
Anderson claims Shepard hasn't been court martialled, so why has he been relieved of his rank, duty and ship?
What is Ashley doing on Earth? What's with the make-up and hair? That style is frankly impractical and hazardous for someone on combat duty, and it seems utterly out of character for someone with the no-nonsense attitude she had in Mass Effect 1.
Why is the Defence Council full of useless idiots? The dialogue in this scene is awfully cheesy as well. "We fight or we die" indeed...
The Reapers shouldn't be invading Earth so early in the game. We've had no opportunity to develop an emotional investment in the location and population beyond what we already possess innately as humans. Because of this and because the invasion has been so heavily hyped in the marketing, the actual moment is frightfully dull. There's just no impact to it, no sense of surprise.
Oh look, they've killed everyone attending the Defence Council session, making the previous scene pretty much pointless except to showcase the invasion. I don't even care that everyone died because, once again, we have no attachment to them. I also don't buy that the only survivors were Shepard and Anderson. It's just too convenient that the two named characters escaped with a few scratches and some bruising while everyone else got pulped. We should see people pulling themselves to their feet, screaming for help, trying to clear the doorway.
Why is all the cool stuff happening in the background? Sure we get a few stray blasts headed in our direction but for the most part all the major action is seperate from the player. We should be on the streets, not wandering about atop a skyscraper. We ought to be in the thick of things, fighting through waves of husks, leading survivors to safety, fleeing and hiding, dodgeing the concrete shattering steps of a Reaper. The sort of thing that might actually generate some excitement. In it's current state the opening manages to feel very rushed, whilst paradoxically lacking any real urgency. The lack of emotional investment I mentioned earlier? Being removed from the action like this doesn't help.
So heat sinks are being reffered to as ammo now? It was annoying enough when they were introduced in a pointless attempt to make the gunplay feel more like a traditional shooter. Now it's as if the writers don't even care enough to keep up the pretense.
The scene with the kid is a weak and obvious attempt at tugging on our heart strings. It fails because his dialogue and behaviour doesn't really gel with the image of a terrified child.
"Everyone's dying" the kid whines, and yet we've barely seen anyone since before the invasion. Look off the edge of the skyscraper and aside from the collossal Reapers (which I'll admit are really cool) and a handful of painfully low resolution 2d humans, the streets look deserted. Where are all the vehicles, the mobilising soldiers, the crowds of fleeing civillians, the wreckage, or the corpses?
Why is Shepard acting so Earth-centric? Paragon Shepard has always recognised that the Reapers represented a threat to the entire galaxy, not just to Humans, and that we couldn't stand by ourselves and expect to survive. I really hate that I'm not allowed to pick what Shepard is saying. Apparently a lot of dialogue options were cut from the demo to save space, but the result doesn't represent what I expect from a Mass Effect game. Couldn't they have cut Character Creation instead? I certainly wouldn't have minded.
This whole gameplay sequence feels too quiet. Aside from the distant explosions, occasional set-pieces and the infrequent action sequences, there are long stretches where not a lot is happening in the audio department. Couldn't we have had some pulse-pounding background music, maybe some panicked radio chatter from the beleaguered defenders? At the very least that might have helped with the urgency problems.
Ashley says over the radio that the Reapers are about to take down a dreadnought. We then see a Reaper blow up what looks to be a relatively small Alliance ship. Certainly it doesn't look much larger than the Normandy. In previous games dreadnoughts were described as being a kilometer long and incapable of generating a mass effect field strong enough allow entry into a planet's atmosphere.
Why does Anderson want to stay ground side? He's too old to be worth much fighting on the front lines, while his high level of military and political experience makes him more valuable in an administration position. He should be taken to the Citadel in order to organise the other races, or otherwise taken to an Alliance millitary installation where he can rally and direct Earth's defenders. Is he still on the Citadel Council? I've heard some sources claim he resigned, but the demo never mentions his position.
And that kid shows up again, and shortly thereafter gets vaporised by a Reaper. Again, an attempt at creating emotional impact, but again it fails because we have no reason to care about him. We barely know him. He had maybe three lines of bad dialogue. We don't even know his name for pity's sake.
Why didn't the child-killing Reaper or any of the others in the area even try to shoot down the Normandy during that overly soppy sequence? It got the shuttles easily enough, and the Normandy was virtually stationary in front of it the whole time. Surely Harbinger has labelled Shepard and the Normandy as high priority targets after the events of the previous games. And why prioritise the civillian targets over the Normandy anyway? I thought the Reapers goal was to harvest organic life, especially humanity if Mass Effect 2 was any indication. I suspect that organics become significantly harder to harvest when they're reduced to so many vaporised particles drifting in the wind. The Reapers should be performing surgical strikes on millitary targets while limiting collateral damage. Instead it almost looks like they're doing the opposite.
Okay well that grew into something rather more...thorough...than I'd intended, but I hope I got my feeling's across. I know some of those point's look rather nitpicky, but as they say, the devil is in the details. While I did enjoy the combat, I can't really say that I've got high hopes for the story quality after this.