I made a little 'Line Bot' program where you can trace a path with the mouse and have the 'lil 'feller follow it (similar to 'Line Rider' with out the physics, though this too could be added with a little work
You can also 'Load' and 'Save' your doodles to disk.
With a little imagination you could replace the background with one of your
own choosing and create paths for other types of program's (Galaga and RPG's come to mind).