Edit in JSFiddle

		var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;

		window.requestAnimationFrame = requestAnimationFrame;

		brick_screen = document.getElementById('gameScreen');
		b_ctx = brick_screen.getContext('2d');
		b_ctx.fillStyle = "white";

		SCREEN_WIDTH = brick_screen.width;
		console.log(SCREEN_WIDTH);
		SCREEN_HEIGHT = brick_screen.height;
		var mousex = null;

		var bricks_game = {
		    playing: false,
		    score: 0,
		    level: 1,
		    boundary: null
		}

		    function getMousePos(e) {
		        mousex = e.clientX - bricks_game.boundary.left;
		    }

		bricks_game.start = function () {
		    console.log("start function");
		    if (!bricks_game.playing) {
		        bricks_game.playing = true;
		        window.addEventListener("mousemove", getMousePos, false);
		        this.boundary = brick_screen.getBoundingClientRect();
		        this.update();
		        console.log(this.playing);
		    }
		}

		bricks_game.update = function () {
		    //console.log('hello');
		    b_ctx.clearRect(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
		    ball.update();
		    paddle.update();
		    paddle.draw();
		    ball.draw();
		    console.log(bricks_game.playing);
		    if (bricks_game.playing) {
		        window.requestAnimationFrame(bricks_game.update);
		        console.log(this.playing);
		    }
		}

		var paddle = {
		    WIDTH: 100,
		    HEIGHT: 10,
		    x: 100,
		    y: SCREEN_HEIGHT * 7 / 8,

		    draw: function () {
		        console.log('draw says hi');
		        b_ctx.fillStyle = "white";
		        b_ctx.fillRect(this.x, this.y, this.WIDTH, this.HEIGHT);
		        console.log(this.WIDTH / 2);
		    },
		    update: function () {
		        if (mousex < 0) {
		            this.x = 0;
		        } else if (mousex > SCREEN_WIDTH - this.WIDTH) {
		            this.x = SCREEN_WIDTH - this.WIDTH;
		        } else {
		            this.x = mousex;
		        }
		    }
		}
		var ball = {
		    WIDTH: 10,
		    HEIGHT: 10,

		    x: 0,
		    y: 0,
		    dx: 5,
		    dy: 5,

		    draw: function () {
		        b_ctx.fillStyle = 'white';
		        b_ctx.fillRect(this.x, this.y, this.WIDTH, this.HEIGHT);
		    },

		    update: function () {
		        this.x += this.dx;
		        this.y += this.dy;
		        if (this.x >= paddle.x && this.x + this.WIDTH <= paddle.x + paddle.WIDTH && this.y >= paddle.y && this.y <= paddle.y + paddle.HEIGHT) {
		            this.dy = -1 * this.dy;
		        }
		        if (this.x + this.WIDTH >= SCREEN_WIDTH || this.x <= 0) {
		            this.dx = -1 * this.dx;
		        }
		        if (this.y <= 0) {
		            this.dy = -1 * this.dy;
		        }
		        if (this.y >= SCREEN_HEIGHT) {
		            bricks_game.playing = false;
		            this.x = 0;
		            this.y = 0;
		            this.dx = 5;
		            this.dx = 5;

		        }
		    }
		}

		    function Brick(x, y) {
		        this.WIDTH = SCREEN_WIDTH / 10;
		        this.HEIGHT = 10;
		        this.x = x;
		        this.y = y;

		        Brick.prototype.isHit = function () {
		        }
		    }

<div>
    <canvas id="gameScreen" height="400" width="700" onclick="bricks_game.start()">Your Browser does not support Canvas.</canvas>
</div>

	canvas {
	    margin-left : 100px;
	    background-color : black;
	}