I downloaded and played the 360 version this morning when it went up, and just finished the PC demo a little while ago.
The 360 version was absolutely dire. Performance-wise, it was about what I'd expect, except for the frame rate tanking in some of the cutscenes, so that wasn't really a disappointment. But the low FOV made it extremely hard to tell just what the fuck was going on, and enemies take goddamned forever to kill when you can't reliably get a headshot from range (on Insanity). It also really sucks that you have to bring up two separate screens to change your weapons and to use abilities, and that you can't move from one to the other without unpausing and repausing the game, but I suppose if you're used to playing Mass Effect on consoles that won't really bother you. I had negative amounts of fun when I played it, and for the last half of the last mission, I was really only playing out of spite.
The PC version was quite a lot better. Obviously performance issues go away, and I'm not sure if the FOV is actually higher or if it's just that you can swing the camera around as fast as you want, but it was a lot easier to keep track of just what was going on around me. Pausing is much nicer, since there's only one button to do it and you can control everybody's weapons and abilities from there, and consistently nailing headshots makes the combat much less painful (the difference in damage between a headshot and a body shot feels a little exaggerated, almost like Uncharted 1). It felt a lot closer to the level of ME2's combat, and I stopped worrying about whether I should just cancel my pre-order entirely.
Non platform-specific things of note:
- That intro sequence was laughable. I don't even give a shit about the story aspects. Fun things to try: When those three Husks climb up the side of that building, in what is obviously a scripted sequence where they are obviously not ever going to actually attack you or pose any threat to anyone, try doing the 'smart' thing and ignoring them. Anderson just goes "You didn't forget how to shoot, did ya?", about three or four seconds of silence pass, and then the entire sequence repeats, with three more Husks climbing up the same building. And at the end, just empty all your ammo into the ground if you want the Normandy to show up faster.
- The music is great, even if it seems horribly out of context to play slow, sad music over top what is clearly a parody of video games trying to resonate with you emotionally.
- If they're going to give you the weapon loadout of a Soldier no matter which class you play, just fucking lock the demo to Soldiers-only and save everybody the headache. It would be funny how useless Sentinel is in the demo if not for the fact that you still have to actually play that shit. Vanguard wasn't a whole lot better. I never tried any other classes.
- Melee sucks, compared to ME2. Like really, really, really fucking sucks. In ME2 it was fast, simple, and appropriately powerful relative to the risk you take in getting close enough to use it - in other words, designed with an eye toward gameplay mechanics, rather than being flashy. In ME3, the attacks you get when you tap the melee button are so ludicrously weak that they really needn't have bothered putting them in the game to begin with, and the wowee lookit that that's badass heavy attacks are slow, can easily miss if the enemy is actually moving, and lock you into a long animation that you can't cancel out of (although you can certainly get shot to death). It's a pretty direct tradeoff: The game lost something that is well-designed, and gained something that is "cool".
- Enemies are gigantic damage sponges, compared to ME2. It seems like they go down at more or less the same speed if every shot you land is a headshot, but body shots deal piddling amounts of damage, compared to the same types of attacks in ME2. Not much of a problem if you're playing it like a cover shooter, hanging back and aiming right for people, but (between this and the melee) it really fucks up playing as Vanguard. Even in the early game of ME2, when being a Vanguard meant dying really easily any time you tried using a Charge, you at least felt powerful doing it. There's nothing wrong with being a glass cannon, as long as you've got a pretty good cannonball. In this demo, even if you Charge to an enemy that's alone, you're still A) likely to get shot once or twice before you kill him, and B) taking twice as long to kill him as you would in ME2.
- The cover system is really fucked up. Try to roll around or sprint in the middle of combat, and you'll find yourself getting stuck taking cover against every exposed surface in the level. If you don't come to a complete stop before you try to take cover, you'll probably roll right past it, and wind up exposed for another couple seconds. And once you're in cover, it seems like the game alternates between it being so easy to get out of cover that Shepard just stands up in front of a heavy turret because you turned to look at what was to your right, slow and sticky when all you want to do is move around the corner of a piece of cover that you're already attached to, and making you press Spacebar to leave cover only for Shepard to roll right out into the most exposed part of the level.
- The enemy AI is what I would ordinarily call much improved, in the sense that they now seem to generally avoid making themselves the easiest targets in the world, and that they will now throw grenades to smoke you out of cover. Unfortunately, due to the above cover issues, this comes off as more annoying than anything. When I see the grenade icon sitting next to me, my first thought isn't "Oh shit, time to move!" It's more along the lines of staring at the grenade for half a second, and then wondering, "Is this actually going to kill me? Because otherwise, I'd rather get partially blown up than try to navigate to a new piece of cover without getting stuck to something."
I was definitely groaning a lot more than I hoped to be, but at least as far as the PC version is concerned, it's fun enough that I'm not really having second thoughts about playing the game.