What a wonderful looking and unique game. I loved the art, animation, audio and sound design. This was a joy to play. That interactive title screen ... very well done. I jumped right in, but I didn't quite get it. But I wanted to see more, so after reading through the description I immediately got the gameplay loop. I wish that was taught during the gameplay, but hey, it's a jam game! I had the same problem teaching mechanics in mine.
Once I did get it, I had a blast earning the different powerups and taking on the boss. My main critique outside of learning the mechanics is I wish there was more feedback on my health and the boss' health. I want to know when I'm in danger and I want to feel like I'm progressing in taking the boss down. Feedback in some way would be great, even if it's not a traditional healthbar. I also wish I had to choose to enter a power-up mini-game. Sometimes I'd be avoiding an attack and just end up in a mini-game.
Overall, what a wonderful entry. I had a great time with this. Your team should be proud.