Oh no, was it the known bug? I'll fix it after the jam ^^' I wanted to fix it but the people I lived with stopped me because it was so late... ah well. I think I'll also add a saving prompt in between worlds so you're not as bummed if something like this happens.
Ah yes, I think that's one of the hardest ones? Here's a tip: once you've gotten yourself on the same horizontal level as the twin, you've basically won. ^^