Right out of the gate that eye is going to haunt me forever, it is absolutely brutal and i intend to defeat it after I finish this review. The game looks and sounds really nice, you did a really great job. The eyes attacks were very readable and presented well. I appreciate that you had a sound for when the player was getting hit and for when they were flying. I also really like the fact that the boss had multiple sounds, it really helped make it more engaging and helped notify me of what to expect next(good game design). I like the idea of the boss fight being broken up into stages and each stage being randomly selected by the die, this is a good implementation of the theme and some rng and it worked great. My only feedback is that I wish there was a sound for when the player hits the boss, it would help make the shooting feel more impactful. Another possible sound could be a shooting sound for the player, however given how much the player shoots that might not be a good idea.
Overall, I really like what you did here and I have not played anything else like it during the jam so great work.