10 lines, no comments · 102 tokens, written in 10 seconds for $0.0001

 1  function setup() {
 2    createCanvas(800, 600);
 3    fill(255);
 4    noStroke();
 5  }
 6  
 7  function draw() {
 8    background(0);
 9    ellipse(mouseX, mouseY, 50, 50);
10  }