Regarding endings that aren't in the game yet, I think the dialogue of the guy in the cave seems unfinished. If I skip-jump while having double jump, my character wants to help but simply can't. After tossing the stone, the caveman seems to forget I visited him before and I can't give him any of my jump powerups, even though I can give my multi-jump to the dog. However, I have no idea what could happen if I helped the caveman get out.