constructor() {

    this.x = random(width)

    this.y = random(0, 10)

    this.diameter = random(10, 70)

    this.speed = random(0, 3)

    this.color = [random(255), random(255), random(255), 100]

  }

  draw() {

    circle(this.x, this.y, this.diameter)

    fill(this.color)

  }

  move() {

    this.speed += gravity

    this.y += this.speed

    if (this.y > height - this.diameter / 2) {

      this.speed *= -0.85

      this.y = height - this.diameter / 2

    }

  }

}

​

let balls = []

​

const gravity = 0.2

​

function setup() {

  createCanvas(400, 400);

  noStroke()

  while (balls.length < 20) {

    balls.push(new Ball())

  }

}

​

function draw() {

  background(220);

  for (let ball of balls) {

    ball.draw()

    ball.move()

  }

}