I really like the main mechanic of having to follow a rythm for attacks, big fan of ryhtm games. I also see inspiration from Vampire Slayers which is cool.
The game was a bit buggy at times, taking damage didn't always work and other that kind of stuff.
Unfortunately, the art was an eyesore, as everything clashed with too much contrast. Next time I recommend looking into minimalistic art styles while also following a simple color palette. This way even programmer only teams can make their games look significantly better.
But good job for your first game, keep learning!