Hello! Thanks for taking the time to review the game. We ran out of time during the jam, and couldn't make a proper 'end' to the game. Literally last-second, we elected to simply reset the stage counter to 0 after the first boss. Turns out, once you've already 'Unlocked' (then subsequently forgotten or placed in your party) all the characters, the game didn't know what else to give you!
Anyway, we're gonna try fixing this by next patch... Maybe...