let y;

let speed;

​

function setup() {

  createCanvas(400, 400);

  speed = 1;

  x = width / 2;

  y = height / 2;

}

​

function draw() {

  background(220);

  circle(x, y, 30);

  if (x < mouseX) x += speed;

  if (x > mouseX) x -= speed;

  if (y < mouseY) y += speed;

  if (y > mouseY) y -= speed;

}

​