I've been told this is the best in the series. If that's the case, I'm not interested.
Graphics - 4/10
I know this is an older PS2 game so of course the graphics won't be absolutely stunning. But I still found them to be a little poor. They are roughly on the same level as the first Devil May Cry, though I would say this game was a step below it. If you are a person that only cares about graphics (or cares about it a lot, anyways) then you really won't care for this one.
Characters - 2/10
Sorry, but these characters seemed as flat as you can get. They didn't have intriguing personalities. They have nothing unique about them. They were really quite boring and I, as the player, didn't find myself caring about what happened to them or their stories.
Plot - 3.5/10
It's a rather cliche story. You've probably heard something similar. Girl gets kidnapped by evil villain (in this case, vampire) and the hero has to go rescue her. Ring a bell? There are a few small twists but I just wasn't able to get into it and feel like I was actually interested in it. It feels like it was paced a little slow.
Gameplay - 5/10
Have you played a Devil May Cry game? Chaos Legion? It might remind you of it. It's a bit of hack and slash, but with a bit of a difference. Your main weapon is a whip, so it's not hack and slash with swords. While it isn't bad gameplay, it starts to make you feel a little comatose at times. It gets old and repetitive rather quickly.
Voice Acting - 1.5/10
Really. The voice acting is pretty laughable. Voice acting isn't really a big deal to me, but I couldn't help but find even some of the series moments a little funny, just because everything seemed either too monotone or too dramatic.
Music - 3/10
It wasn't anything special but it wasn't bad either. The music tracks didn't really stand out, in a good or bad way. It was just background music without an impact.
Replay Value - NA
I must admit that I didn't make it to the end. I just couldn't feel absorbed in the game and I lost interest. For me, there is no replay value, but there may be unlockable goodies at the end.
Overall? It seems like a game you probably would either love or hate. As for me, I'm closer to the hate side. I found it to be dull and boring overall, lacking interesting characters and plot points, and just a forgettable gaming experience.
On the bright side, if you still want to play it, you can get it very cheap Used so buying it and disliking it isn't too big of a loss.
If you're looking for a game to get you hooked into the Castlevania series, this may not be the right one. It certainly wasn't for me.