I spent a chunk of this evening refactoring the code I wrote on Sunday into packages. I doubt this will pay off in terms of the time spent, but I do think this kind of organisation helps to mitigate bugs a bit, by limiting the amount of stuff you're accessing out of the global namespace and which therefore may not be in the right state.
After that I added jump direction indicators, then I started work on SVG-editable levels. The actual graphics + physics for that dropped out quite quickly, but parsing SVG paths is a pain. Seems I had forgotten this since I last attempted it (was it PyWeek 10?).
Anyway, this lets me start to think about level design, but I'm going to have to do something special with those ugly rock graphics. Tomorrow might end up being an art and design day.