【練習】ジャンプゲーム（おもしろくないなぁ～）

/**
 * Copyright Tamanegi_kenshi ( http://wonderfl.net/user/Tamanegi_kenshi )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/b7RC
 */

package {
    import flash.display.Sprite;
    import flash.events.*;
    import flash.text.TextField;
    public class FlashTest extends Sprite {
        
        private var ball:Ball;
    private var ball2:Ball;
        private var gravity:Number =1;
        private var vy:int =-20;
        private var _text:TextField;
        private var speed:Number=4;
   
        
        public function FlashTest() {
            
            ball =new Ball(0x00000,20);
            addChild(ball);
            ball.y=420;
            ball.x =30;
            
            ball2 =new Ball(0x00000,50);
            addChild(ball2);
            ball2.y=390;
            ball2.x =400;
            
            _text =new TextField();
            _text.text="MOUSE CLICK";
            addChild(_text);
            
            this.graphics.lineStyle(1);
            this.graphics.moveTo(270,250);
            this.graphics.lineTo(270,440);
            
       stage.addEventListener(MouseEvent.CLICK,click);
       addEventListener(Event.ENTER_FRAME,onEnter);
       }
       
       private function onEnter(event:Event):void{
           ball.x +=speed;
           if(ball.x>=250 ||ball.x<20){
               speed*=-1*1.2;
               
               }else if(speed>10){
                   speed=10;}
               
           ball2.x -=10;
           if(ball2.x<-50){
               ball2.x =stage.stageWidth+50;
           }
           
           var dx:Number =ball.x-ball2.x;
           var dy:Number =ball.y-ball2.y;
           var a:Number=Math.sqrt(dx*dx +dy*dy);
           if(a<60){
               removeEventListener(Event.ENTER_FRAME,onEnter);
               removeEventListener(Event.ENTER_FRAME,on);
               addChild(_text);
               _text.text="OUT!!"
               }    
    }
    
       private function click(event:MouseEvent):void{
       
           addEventListener(Event.ENTER_FRAME,on);
           }
        private function on(event:Event):void{
        vy+=gravity;
            ball.y+=vy;
            if(ball.y>420){
                ball.y=420;
                vy=-20;
                removeEventListener(Event.ENTER_FRAME,on);              }
            }
            
        
    }
}

import flash.display.Sprite;
import flash.display.GradientType;
import flash.geom.Matrix;

import flash.accessibility.Accessibility;
class Ball extends Sprite{
    public function Ball(color:uint=0x000000,size:int=10){

            
            
            graphics.beginFill(color);
            graphics.drawCircle(0,0,size);
        graphics.endFill();
    }    
}