I also have a question about the gameplay, sometimes if you look up and press attack and jump at the same time, the knight goes flying up to the top of the screen. I think someone mentioned this in the cart you posted on Lexaloffle as well.
I know this comment is very late, considering the game jam was in 2018, but this is a great game. The platforming to charms is pretty difficult but fun to get through, and the boss battles weren't impossibly hard.