32 lines, no comments · 270 tokens, written in 2 seconds for $0.020

 1  let x, y;
 2  let xSpeed, ySpeed;
 3  let ballColor;
 4  
 5  function setup() {
 6    createCanvas(400, 400);
 7    x = random(width);
 8    y = random(height);
 9    xSpeed = random(2, 5);
10    ySpeed = random(2, 5);
11    ballColor = color(random(255), random(255), random(255));
12  }
13  
14  function draw() {
15    background(0);
16    fill(ballColor);
17    noStroke();
18    ellipse(x, y, 30, 30);
19  
20    x += xSpeed;
21    y += ySpeed;
22  
23    if (x < 15 || x > width - 15) {
24      xSpeed *= -1;
25      ballColor = color(random(255), random(255), random(255));
26    }
27  
28    if (y < 15 || y > height - 15) {
29      ySpeed *= -1;
30      ballColor = color(random(255), random(255), random(255));
31    }
32  }