I played some of the demo from Official Xbox Magazine's game disc and thought it was pretty cool. Looks very slick. Haven't heard too much about it otherwise. Apparently there's already a sequel released (or pending) in Japan.
I've had more time to play this game and it just keeps getting better and better. Anyone contemplating buying this game should. It is one of the coolest games I've played on the Xbox!
Finally got it, as it has been sold out around here. The gameplay is also a bit off from what I was expecting. I imagined it would be lightning fast and responsive like Shinobi, but the character is a bit slow and floaty. The hint of Gunvalkyrie thrown in is cool. I should also note that it runs at 30FPS rather than the standard 60FPS and it does hurt the impact the graphics make compared to something like ZOE2. Overall, I'd put this game in the middle tier of 3D hack and slashers. It's definately no Devil May Cry, but rather another in the long line of good entries that are just short of being great such as Buffy, Shinobi, and Rygar.
It looks better in 4:3 than in 16:9, but then again, I haven't come across too many demons to have a good point of reference of what the right ratio would be.