let cy = 0;

​

function setup() {

  createCanvas(400, 400);

  // start circle in center of screen

  cx = width / 2;

  cy = height / 2;

}

​

​

​

function draw() {

  background(220);

  // move x 1% of distance to mouse

  cx += (mouseX - cx) * 0.01;

  // move y 1% of distance to mouse

  cy += (mouseY - cy) * 0.01;

  circle(cx, cy, 20);

}