Just played through the first stage solo. It's okay. I didn't expect there to be the usual Symphony of the Night-like features like a Bestiary and Item Compendium, which is definitely cool. I didn't know what to think of randomized items in the stages at first, but I am kind of digging it after playing it for the hour that I did. I don't really like the menu design and look, but the game looks fine, even though I'm sure it reuses 100% of previous Castlevania assets. The music is good, as expected, but for some reason I think the slower pace of the characters doesn't make the game feel as explosive as it should feel. It's just not that exciting.
If a few of my friends decide to DL it I am sure it would be more fun. I really hope this game does well enough so Iga can return to 3DS and make a true, complete Castlevania title. Castlevania HD just seems like a fan service appetizer until the real meal is ready.