I appreciate you taking your time to share your detailed thoughts! And thank you for finishing the game!
When deciding on the boss fight mechanics, I wanted them to speak for themselves so the player could understand them by simply playing. I was afraid it would not be very clear and people would get frustrated. I'm glad that's not the case, and I'm glad you enjoyed it!
I totally agree the Cream fight can use some polish, I didn't have enough time to get it working as I would've wanted, and the way objects fall is definitely the first thing I'll fix whenever I decide to continue working on the game.