Thank you so much for the in depth feedback - knowing your thoughts as you played it is super useful for us!
We're really sorry about the experience with the boss. You should be able to shoot straight at the light balls, but the hitbox bugged in a way that wasn't present during our playtesting with others, which is really unfortunate (same with the music). We'll no doubt patch it as soon as the jam voting is over, but thanks for sticking with it to reach the end!
Thanks for all the platforming feedback too! It's our first platformer, and only the second game we have ever made, so this feedback is SUPER helpful to us, thanks so much!