Hi! Musician/level designer here. Glad to hear that you liked the music! Comparing it with kirby is a very good compliment! :D
About the checkpoint.. Yeah, I misplaced the last one so it wasn't working. :( Too bad, if you die in the last screen, the game sends you back to the toughest section. I only noticed it after the voting phase started. We already fixed it for a post jam version, but it seems to bother a lot of people here (and with good reason).
Anyways, thanks for the feedback!