This is a cute use of the theme! I like a spinning record as a boss, it's a good visual center-point for the boss fight. The fight itself didn't work for me though, I never saw a projectile from the boss. Also, the tutorial could use the main WASD controls listed, it was hard to determine what the basic control scheme was before diving in given I was only given info on the invincibility bar. I'm not sure how well Minecraft music would be suited to a rhythmic boss fight, but I'm definitely curious how it's supposed to play out!