All songs, a few foods, and the bosses presented in semi-random order for you to fight your way through. And if you make it through, the game would record your time to give you something to beat! Alternatively, it could score you based on both time and how much health and food you have left at the end.
If this already exists as a mod, I'd love to see it. I haven't really messed with the editor yet, so I don't know how easy it would be to make something like this. If worse comes to worse and I can't handle doing this I may just take the lazy way out and get a bunch of save files before bosses so I can pretend I'm playing boss rush.

Anyway, it's just an idea that popped into my head when I realized I wanted to replay some of the bosses but had no means other than to start a new game.
Perhaps you could keep it in mind for Aquaria 2 if it ever comes out.
