Press the space button to clear the board, the down arrow button to set the pen down, the up arrow to lift the pen, the right arrow to grow the pen thickness, and the left arrow to decrease the thickness. Try this: Press the right arrow until the pen thickness takes up all of the screen, and than press the left arrow repeatly or hold it in till you have created a circle containing many rainbow rings! Experiment to make more rainbow pen art!
I learned how to create this by a scratch tutorial a little while back.. (Some things i added personally.)
