let xSpeed = 1;

let ySpeed;

​

function setup() {

  createCanvas(500, 400);

​

  x = width / 2;

  y = height / 2;

  ySpeed = (height / width) * xSpeed;

}

​

function draw() {

  background(220);

​

  ellipse(x, y, 50, 50);

  if (x < mouseX) x += xSpeed;

  if (x > mouseX) x -= xSpeed;

  if (y < mouseY) y += ySpeed;

  if (y > mouseY) y -= ySpeed;

}

​