let y = 100;

let xSpeed = 1;

let ySpeed = 3.3;

​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(220);

  x = x + xSpeed;

  y = y + ySpeed;

  if (x > width || x < 0){

      xSpeed = xSpeed * -1;

      }

  if (y > height || y < 0){

      ySpeed = ySpeed * -1;

      }

  ellipse(x, y, 16, 16);

}