Ah shoot, the way I'm painting images from tilesets is apparently only supported with different arguments in FF. It doesn't count for the JAM, but here's an updated build with a fix for that applied: <REDACTED>. EDIT: Just saw the rules don't allow linking to other versions and removed it, sorry!
If you run out of levels and want to play with it a little bit more, ctrl+M on the main menu will bring up the map editor! Once you've made a map you like, you can hit ctrl+G to play it. :)