var by;

var diam;

var vx;

var vy;

var radius;

var score;

​

function setup() {

  createCanvas(500, 500);

  diam = 40;

  radius = diam/2;

  bx = radius;

  by = 200;

  score = 0;

  vx = 6.0;

  vy = 3.0;

}

​

function draw() {

  rectMode(CENTER);

  background(255, 200, 200);

  let yc = constrain(mouseY, 0, height);

  rect(450, yc, 12, 60);

​

​

​

​

  fill(0);

  ellipse(bx, by, diam, diam);

​

​

​

  if (yc - 30 <= by && by <= yc + 30 && bx > 444 - radius && bx < 450 - radius) {

    vx = -vx;

    score++;

  }

​

  if (bx < radius) {

    vx = -vx;

  }

  if (by < radius || by > height - radius) {

    vy = -vy;

  }

  if (bx > width - radius) {

    push();

    textAlign(CENTER);

    textSize(50);

    text("GAME OVER", width/2, height/2);

    pop();

  }

  textSize(24);

  text("score: " + score, 10, 30);

  bx = bx + vx;

  by = by + vy;

}