Oh no, I know exactly what's wrong. The game is supposed to boot you back to the main menu, but I did some last minute menu work and wound up changing the filepath of the main menu scene. Problem is, the losing code is like the only place where I used a direct path string, so it tries to load an invalid path. This sucks.
Viewing post in Head in the Clouds jam comments
8) No new content may be uploaded after the submission deadline (no music, no polish, no tweaks). The only approved changes are GAME BREAKING bug fixes. Please include other bugs (e.g. doesn’t play in full-screen, etc.) as information on your entry’s page.
I'd say this counts as game-breaking (a trial-and-error game that won't let you trial-and-error sounds pretty broken to me), so that's a relief. I'll submit a fix in a bit.