Played the demo my thoughs:
Graphics: Great visuals, love the rain effect's, love the artstyle, it's probably the best looking game on the 360 currently and the atmosphere make you feel that the world is in peril, didn't notice any frame rate dips.
Music: Like what I've heard so far. Cinimatic orchestra that totaly fit's the mood of the universe, I can see why they didn't go with Yamane's style since it would be out of place. But I'll miss the catchy themes the series is known for.(I was happy that the classic game over music play's when you die)
Gameplay: It would be easy to just sum it up as " God of War clone" but im not gonna do that. The controls are tight, when you hit something it feels like your hitting your opponent. The game also takes cues from Lament of Innocence with the direct attacks and the wide attacks as well as the blocking. Im glad Mercurysteam decided to go with the L2-left stick dodging mechanic than the right stick Mechanic(which does nothing apparently). The enemies take alot of damage out of you so blocking and dodging won't get you far, I went in button mashing like God of War and got my ass whooped like Ninja Gaiden.(Played it on normal BTW)
Overall: I was impressed, gameplay is tight, visuals are great, music will probably be in a mixed bag but hey SOTN didn't have familiar tracks outside of Dance of Illusions. The only thing that bugged me or will bug me is the fixed camera but that comes with the territory with action games. Kinda wish they put some of the platforming elements into the demo but oh well the game comes out tomorrow.