Great game! I think that this is a really good concept and base for a bigger project! It does a great job of giving the overall vibe of Castlevania, while being completely unique and original. Graphics are great and gameplay is smooth. I will say though, I think the sound design might need a bit of work. That impact sound effect is really loud and threatens to blow up my speakers every time. Without getting to complicated, I would recommend to make it quieter and add some reverb (not too much, you definitely don't want to overdo it!).
So yeah, great game, and I'm excited to see if this game gets a full release! 9.5/10 from me.