Running square

function setup() {
  createCanvas(400, 400);
  angleMode(DEGREES)
}

function draw() {
  background(255);
  
  push()
  stroke(0, 50)
  translate(cos(frameCount * 0.12) * 20, 0)
  line(100, 200, 300, 200)
  translate(cos(frameCount * 0.23) * 20, 0)
  line(100, 200, 300, 200)
  translate(cos(frameCount * 0.41) * 20, 0)
  line(100, 200, 300, 200)
  pop()
  push()
  stroke(0, 150)
  fill(255)
  translate(sin(frameCount) * 10, 0)
  translate(245 - frameCount / 90 % 1 * 50, 200)
  rotate(frameCount % 90 + 180)
  square(0, 0, 50)
  pop()
}