From my point of view, the backgrounds are more realistic, more about architecture and baroque detail than Kid Icarus'. The transition between the great room with the chandelier and the underground zone is so smartly done, so detailed... so are the broken segments of the same room´s vault, which let you look outside the building, for example. You know, things like those.
The 3d effects are less about "fireworks" and more about atmosphere which I feel it's the right approach in Castlevania (well, aside flea-men thrown at your face, that is).
The fixed camera angular movements and zooming is a plus because, like in LoS, it looks very theatrical, giving you moments of architectural awe mixed with the dramatic zooming during the encounters. Needless to say, it work far far better in a side scroller than in a full 3d title, becuse you dont miss controlling the camera. I always loved those SotN litle sections without enemies, just for you to enjoy the suroundings, well it's reminiscent of that.
The menus and interfaces are detailed and polished. It feels like a very well finished product, as LoS was.
Oh, by the way, the music is far from the heavy melodic tunes we all miss, but I´m enjoying it more than LoS'. Anyway, It was just 10-15 minutes of demo, we will see.