I just pre-ordered the game today, I wanted that demo. And I must say I'm glad I did, here are my initial impressions.
-Graphics- The graphics look amazingly good, I was worried at first. I was overjoyed to see that the demo had a widescreen mode: that makes it look so much better on my t.v. since I have an enhanced mode. There seemed to be some bland textures here and there, but it gave the game a solid clean look, and I'm sure helped with frames (which seemed very fluid.)
-Sound- Heh heh, the soundtrack is just absolutely gorgeous. Very epic feel and enhanced the atmosphere greatly. Sound effects and whatnot complimented the experience. I was also pleased to find that the voice acting was believable as well, although there wasn't too much in the demo, what was there did not disappoint at all.
-Gameplay- Rock Solid. Combos were easy and fun and that is just the surface, I can't wait to see what new abilities the final game will have. Some mini-game aspects were also quite enjoyable, and animated beautifully. There were a couple puzzle elements that were pretty seamlessly added into the level. The short bit of platforming controlled very well, another thing that can be a huge drag if not done right.
I grinned practically the whole time I played this fantastic little appetizer. March 22nd can't come soon enough.