Drag anywhere on the canvas to draw a soft, glowing trail behind your finger or cursor. Lift and start again, and the color gently shifts to the next one in a calm rotation.
There's no score, no goal, and nothing to get wrong — it's closer to a fidget toy or a sand garden than a game. Some people use it as a short palate cleanser between other games on this site; others just leave a doodle running while thinking through something unrelated. Tap "Clear" whenever you want a blank canvas again.