как исправить бликинг шаров в канве?

var ctx;
var H = 800;
var W = 800;

window.onload = function() {

  ctx = canvas.getContext("2d");
  canvas.width = W;
  canvas.height = H;

  function ball(color) {
    //life - the amount of time to show the ball in the screen
    this.life = 60 * 1000; //1 minute
    this.color = arguments.length == 1 ? color : 'white';
    this.x = Math.round(Math.random() * W);
    this.y = Math.round(Math.random() * H);
    this.radius = 10 + Math.round(Math.random() * 50); // between 10-60
    this.dx = 1 + Math.round(Math.random() * 5); //between 1-6
    this.dy = 2 + Math.round(Math.random() * 4); //between 2-6
    this.startAngel = 0;
    this.endAngel = 2 * Math.PI; //360deg 
    this.speed = 3 + Math.round(Math.random() * 50) //3-50msec
    this.show = function() {
      //first clear the previous ball 
      ctx.beginPath();
      ctx.fillStyle = this.color;
      this.x += this.dx;
      this.y += this.dy;
      if (this.x < 0 || this.x > W) {
        this.dx = -this.dx;
      }
      if (this.y < 0 || this.y > H) {
        this.dy = -this.dy;
      }
      ctx.arc(this.x, this.y, this.radius, this.startAngel, this.endAngel);
      ctx.closePath();
      ctx.fill();
      this.life -= this.speed;
    }
  };

  orangeBall = new ball('orange');
  blackBall = new ball('black');
  
  whiteBall = new ball('white');
  yellowgeBall = new ball('yellow');
  pinkBall = new ball('pink');
  blueBall = new ball('blue');
  greenBall = new ball('green');
  
  var balls = [orangeBall, blackBall, whiteBall, yellowgeBall, pinkBall, blueBall, greenBall];
  function mainLoop(){
      ctx.clearRect(0, 0, canvas.width, canvas.height);
      for(var i = 0; i < balls.length; i++){
          if(balls[i].life > 0){
              balls[i].show();
          }
      }
  
  
     requestAnimationFrame(mainLoop);
  }
  requestAnimationFrame(mainLoop);
  
};

html,
body {
  margin: 0;
  padding: 0;
  background: black;
}

.container {
  width: 900px;
  margin: 0 auto;
}

#canvas {
  background: #8613eb;
  border: 1px solid #cbcbcb;
}

<div class="container">
  <canvas id="canvas">Your browser doesn't support this game.</canvas>
</div>

var ctx;
var H = window.innerHeight;
var W = window.innerWidth;

window.onload = function () {

	ctx = canvas.getContext("2d");
	canvas.width=W;
	canvas.height=H;

	function ball(color) {
		//life - the amount of time to show the ball in the screen
		this.life = 60*10, //duration of 600 X 16ms(fram per sec)
		this.color = arguments.length==1 ? color: 'white';
		this.x= Math.round(Math.random()*W);
		this.y= Math.round(Math.random()*H);
		this.radius= 10 + Math.round(Math.random()*50);// between 10-60
		this.dx=1+ Math.round(Math.random()*5); //between 1-6
		this.dy= 2+ Math.round(Math.random()*4); //between 2-6
		this.startAngel= 0;
		this.endAngel= 2*Math.PI; //360deg 
		this.start = null;
	};
	ball.prototype.show = function() {
			//lets stroke the ball
			ctx.beginPath();
			ctx.fillStyle = this.color;
			this.x+=this.dx;
			this.y+=this.dy;
			if (this.x<0 || this.x>W) {
				this.dx=-this.dx;
				}
			if (this.y<0 || this.y>H) {
				this.dy=-this.dy;
				}
			ctx.arc(this.x,this.y,this.radius,this.startAngel,this.endAngel);
			ctx.closePath();
			ctx.fill();
			this.life--;
		};
	var arrBalls = [] ;
	arrBalls.push(new ball('orange'));
	arrBalls.push(new ball('black'));
	arrBalls.push(new ball('white'));
	arrBalls.push(new ball('pink'));
	arrBalls.push(new ball('blue'));
	arrBalls.push(new ball('green'));
	
	// This loop shell be less then 10ms inorder not to maintain
	// 60fps interval of screen hardware rendering
	var balldeth = 0;
	function paint() {
			//clear the canvas once in xframes
			ctx.clearRect(0,0,canvas.width,canvas.height);
			//paint balls in the canvas
			for (var i = 0; i < arrBalls.length; i++ ) {	
				arrBalls[i].life >= 0 ? arrBalls[i].show() : ++balldeth;
			}	
		(balldeth == arrBalls.length) ? console.log("game over"):window.requestAnimationFrame(paint);
	}
	
	window.requestAnimationFrame(paint);
	
};

			html,body {
				margin: 0;
				padding: 0;
				background: black;
			}
			#canvas { background:#8613eb; border:1px solid #cbcbcb; }

	<body>
		<canvas id="canvas">Your browser doesn't support this game.</canvas>
	</body>