Starting to improve

I started to update this game, following the Improve Your Game jam. I'm planning to add save/restore, audio,  and proper navigation (point&click instead of arrows). So far, I reorganized the sources and assets, so each scene is in its own directory, and there is a script to rebuild the sprite atlas from all the assets.

I'm not uploading the updated version yet, because it's not tested enough. Maybe I'll upload only the final update.