the game works fairly well - I love the idea of an rpg bullet hell. I think the core concept is excellent and you could do an awful lot with it!
That said, the audio is really harsh, the UI needs a lot more thought - it's often difficult to read and feels cramped even though there's a ton of empty space. The difficulty curve is a nightmare, but I'm sure you're already aware of that ;) hitboxes are WAY too big, pixel-perfect collision just doesn't work for bullet hell games (I think that's also where the performance issues a couple of people mentioned come in).
It needs a lot of polish and refinement, but for a jam game there's an awful lot of content - so congrats on that! I didn't play the vast majority of it because it was too difficult, but I can see there's a lot there :) I think a broad summary would be: awesome concept, needed more time spent on polish, less time on content.