Move the mouse around to paint. Hold the left mouse button for a bigger pen. Press space to show/hide the variables, which you can adjust.
A little bit of Scratch nostalgia. These kinds of projects are super easy to throw together and super fun to kill time with. This is actually the first time I made one of these things, despite downloading way more than I'd like to admit to back in the day. I'm not a big fan of basic projects, but this one arose from a sudden urge to become a "real" Scratcher like the early 1.4 era cool dudes.
