Naturally, with any game that involves a character creation tool, I must spend hours tweaking my character, until I have the proper aesthetic. Right off the bat, I see something that makes me happy beyond belief... a code system. That's right, there is a code system so that I can (I imagine) create my perfect character now, copy the code, and then when the game finally ships, I can just plug the new code in and be ready to jam as the Shepard I spent so many hours painstakingly crafting... It also means that should I choose, I could offer the code to others so they could then see what my Shepard looks like. But, that is something for another day. Suffice to say, there will be much time spent crafting potentially multiple Shepards, that's just my level of obsession.
There also appears to be three basic types of play, one that is action-based, one that is story-based, and one that is a mixture of the two. This is not to say that the story won't be the same in each style, but rather it will directly influence the game plays. Or more accurately, the difficulty level of each. If you're looking to see how the trilogy finishes, rather than looking for a challenge, the story mode is going to be more your style.
So to avoid spoiling anything for people who have not played the previous games in the series, I'll just say that when the game gets past the initial dialog cinematics, the game moves into an appropriately apocalyptic scenario. Shit hits the fan, and then it just keeps coming, setting things up for what promises to be a great game.
Biggest gripe with the demo, is that it is slightly disjointed. You play through an introductory section, and then are whisked away to some unspecified future point in the story... so in essence, playing the demo actually can act as a bit of a spoiler for later in the game, and I don't much care for spoilers. And then, just like that, it's over...
I'd consider this demo more of a teaser than a proper demo. But either way, consider me very eager for March 6th when this game will finally be in my hands.