i downloaded the rom as well, I just could not wait even a few more days for a taste.
Graphics are top notch. fewer gratuitous effects than HoD (from the little I played of HoD) but even better art quality. A nice balance between graphics and sound, the music this time is on a par with CoTM.
Difficulty does seem to be very much like CoTM. Part if this is due to the akwardness of playing with a keyboard, but i did die a few times in the very first area.
there is obviously a *lot* of depth to the story, probably at least as much as SoTN, maybe more. It's all in Japanese though, so I have no idea what that story actually is.
As for game lenght, well I have heard from those crazy people that actually played through the rom that it is fairly short, and can be beatened in 7-8 hours with the bad ending, but that there is likely two or three times as much playtime to get the good ending. In fact I have heard there may be several endings. I have also heard rumour of a very interesting revelation about soma cruz...
One thing I have to say is that the areas are much more closed in and claustraphobic than in CoTM, lots of narrow cave like pasages, and lots of platforms that are *just* out of reach..
I can't wait for this game to hit the stores, I am convinced it will be top notch..