I went with RPG mode and it's the same ME we know. There's like a cinematic mode where the game makes ALL the decisions for you but I haven't tried because that's for dumb dumbs.
Anyways, this is very early but even then it's still impressive. It's the same thing as ME2 but with more options.
Shooting is better. You can now shoot without aiming (could you do this in ME2 I don't remember).
Rolling makes combat even more smooth. I have been replaying GTAIV lately and going from that game to ME3 demo is like going from awkwardly masturbating when you're a 13 year old when you find out your ding a ling feels good when you touch but don't know what to do with it to full on sex (ME3).
It's fast, it's fun, and there are even more enemy types than in ME2 to keep you on your toes, based on the areas in the demo.
Let's get something out of the way though. The most impressive thing about this demo is by far the customization. If you've read through the thread or posted with us when ME2 came out, you'll know that my biggest problem with ME2 were the customization options. It had the customization depth of a Ratchet and Clank game, that is to say, very shallow.
But ME3 -- and this is just the demo, remember -- has far more customization options than ME1 and 2 combined.
You have the base stats: fitness, combat mastery, incendiary ammo, the usual. The great thing is that EVERY -- and I mean every -- stat has its own skill tree.
So fitness would go like this:
Fitness -> durability -> melee damage. After that you can pick between specific skills like melee synergy shield recharge, fitness expert. It gives you a lot of options depending on your play style and the best thing is that each stat you can pool skill points into has its very own unique list of skills.
So combat mastery has stuff like headshot damage, or henchmen damage, or weapon master.
The story segments were impressive and I'm interested in seeing where the story goes but, although I picked rpg mode, I noticed that the game gave you far less opportunities to say what you want, which was weird, but it's also a pre-alpha demo.
Finally, the soundtrack. I'm one of the people who was disappointed by ME2's soundtrack and I'm not worried about ME3's soundtrack in the least bit.
Also, it looks like minerals are back. If you go to the main menu, the same ME2 platinum;etc stuff pops up in the menu.
Good stuff. If you liked Mass Effect 2, you will more than likely enjoy this.