function setup() {

  createCanvas(600, 400);

}

​

function draw() {

  background(20);

  ellipse(x, y, 25, 25);

  // x++; // make the ball move to the right of the screen

  // x--; // make the ball move to the left of the screen

    // x = x + 1, y = y - 2/3;// make the ball move to the top right corner of the screen

  // x = x - 1, y = y - 2/3;// make the ball move to the top left corner of the screen

  // x = x + 1, y = y + 2/3;// make the ball move to the bottom right corner of the screen

  // x = x - 1, y = y + 2/3;// make the ball move to the bottom left corner of the screen

  x = x - 10, y = y + 20/3;// make the ball move 10 times faster

}