It's an alright game, pretty good for a first jam game. I think the big problem is that it feels very unfair instead of difficult. It's not easy to predict the boss' movements/bullets, and the movement is very slippery and hard to be precise so you can dodge. I'd also prefer holding down the button to shoot.
I do like the graphics a lot, though, they're very clean. I also liked how hovering over stuff changes the color, that's really nice.
Overall, it's very good for a first jam game, it just needs a lot of polish.