HTML做新飞机大战射击游戏代码

新飞机大战射击游戏是一款好玩的基于html5 canvas制作的战斗机射击类网页小游戏源码。没有图片，用CANVAS就可以做出的精致小游戏。
引入js文件
    <script type="text/javascript" src="js/Sound.js"> </script>

    <script type="text/javascript" src="js/Background.js"> </script>
    <script type="text/javascript" src="js/Mouse.js"> </script>
    <script type="text/javascript" src="js/Loader.js"> </script>
    <script type="text/javascript" src="js/FloatyText.js"> </script>
    <script type="text/javascript" src="js/Keyboard.js"> </script>
    <script type="text/javascript" src="js/Collision.js"> </script>

    <script type="text/javascript" src="js/AfterEffect.js"> </script>
    <script type="text/javascript" src="js/PeaShooter.js"> </script>
    <script type="text/javascript" src="js/Laser.js"> </script>
    <script type="text/javascript" src="js/LevelDirector.js"> </script>
    <script type="text/javascript" src="js/Sortie.js"> </script>
    <script type="text/javascript" src="js/Enemy.js"> </script>

    <script type="text/javascript" src="js/Powerup.js"> </script>
    <script type="text/javascript" src="js/Shot.js"> </script>
    <script type="text/javascript" src="js/EnemyShot.js"> </script>
    <script type="text/javascript" src="js/Ship.js"> </script>

    <script type="text/javascript">