18 lines, no comments · 766 tokens, written in 8 seconds for $0.0022

 1  let x = 200;
 2  let y = 200;
 3  let xspeed = 3;
 4  let yspeed = 2;
 5  
 6  function setup() {
 7    createCanvas(400, 400);
 8  }
 9  
10  function draw() {
11    background(220);
12    fill(255, 0, 0);
13    ellipse(x, y, 50, 50);
14    x += xspeed;
15    y += yspeed;
16    if (x > width || x < 0) xspeed *= -1;
17    if (y > height || y < 0) yspeed *= -1;
18  }