I got the game on release and having a lot of fun with it. It reminds me of a Soul Calibur meets Power Stone type of gameplay. Every character plays differently. The combat is simple enough, at least by using the GC controller. I hear it's fun to play online. Castlevania fans will definetly get more out of this than casuals. It's quite amusing to see characters interact with each other from other parts of the series.
My only gripes are that the combat system could've been deeper ie more moves, or at least more than one Finisher per character. The camera is a bit wonky, not bad enough to be a dealbreaker. The character design I didn't like at first, but has grown on me. Otherwise a lot of fun if you're willing to give it a chance.