Unfortunately I didn't have much time by the end of the jam to explain a lot of the mechanics in the game, so I totally get it. There is also unfortunately a bug with the bosses animation in this build for whatever reason (that I somehow didn't catch...) which causes them to not shoot projectiles half the time. The idea is supposed to be it shoots projectiles relatively frequently, and you'd press F to deflect them back at it, buut it is a little hard to know that without a proper tutorial haha.
Also agreed on the UI! It was basically my first real attempt at making a (semi) stylized UI, and I definitely see how that can kinda be detrimental to gameplay. Will definitely keep that in mind for next time!
Yea I felt like you have to use your sword on them, but that didn't work for me, so I don't know if it was bugged or maybe I was just missing it. It was hard to test with how little of them spawned. Also it was hard to see when a projectile spawns when fighting enemies, so maybe having some type of sound that it's coming would help.
There actually is a sound! It's honestly just really quiet though. But yeah, the boss projectile spawning was a bit bugged, unfortunately. Whenever I'd re-export the model for it from Blender, it'd wipe my animation data in Godot, and that was where the projectile spawning logic was being called from. If I had more time I deeeefinitely would have improved this aspect of the game though, very thankful for your feedback!