There should be a mod that takes all the theories and crams them into a game...
Jenka's got the weight of the island on her shoulders... After beating Ballos, there will be a picture of Jenka pushing the island back up... with the power of puppies.
Also, on Jenka theories... perhaps there is a way Jenka will live on after dying, like Yoda. After all, Ballos and the Doctor don't seem to exactly die due to his evil wild magic. Perhaps Jenka, witch with the power to control the dead, has some trick up her sleeve.
She can make life potions that restore all your life at once, so whose to say she doesn't have a secret potion she's saving for the right time...
Lastly, just going to throw this out there, perhaps Jenka and Misery switched bodies at the end. For some reason Misery just disappears after you beat her at the Undead Core. Perhaps Jenka snatched her up, and Misery (Jenka) told Balrog to go take you off this island. Her plan was accomplished, Curly fufilled her role, and no more curse to stop her from taking over Misery.
That was the purpose of the Demon Crown, a way to stop Jenka from taking her over, but she didn't expect the curse...
In the credits, that's Jenka standing there, because we know Jenka likes to stand on the ground, while Misery enjoys floating...