Yes, I played it, and I'm actually using Yoko as avatar cause apparently she's finally coming soon as DLC character.
HD is a loot game. If you've been a completionist in prior 2Dvanias, this will be your heaven (and your hell as well, as instead of enemy drops - those exist but are not really much - you get good stuff through random chest drops, although every stage has its own exclusive stuff).
Unfortunately, and the demo also really sucks badly - Alucard is one of the less interesting characters to start out with, and not being able to keep stuff in a loot game is pretty meh. Not to mention it's single player.
Single player is alright, but it can be incredibly boring, tiring, and when you start out, extremely difficult. In fact already the second stage's boss is pretty much impossible to beat alone when you start out.
However, if you get a couple of friends together (playing with randoms online isn't really a good choice), they can help you getting through the stages and aid you in getting stuff. It can be really a blast, especially when you play with other Castlevania fans.
HD has a lot of potential to be good, unfortunately only if you have a few people online to play with, otherwise it is not as interesting.