<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" width="600" height="400" frameRate="100" creationComplete="creationComplete()" enterFrame="enterFrame(event)" currentState="MainMenu">
    <mx:states>
        <mx:State
            name="Game"
            enterState="enterGame(event)"
            exitState="exitGame(event)">
        </mx:State>
        <mx:State name="MainMenu">
            <mx:AddChild relativeTo="{myCanvas}" position="lastChild">
                <mx:Button x="525" y="368" label="Start" id="btn Start" click="startGameClicked(event)"/>
            </mx:AddChild>
        </mx:State>
    </mx:states>
    <mx:Canvas x="0" y="0" width="100%" height="100%" id="myCanvas"/>
    <mx:Script>
    <![CDATA[
        protected var inGame:Boolean = false;
        public function creationComplete():void
        {
        }
        public function enterFrame(event:Event):void
        {
            if(inGame)
            {
                GameObjectManager.Instance.enterFrame();
                myCanvas.graphics.clear();
                myCanvas.graphics.beginBitmapFill(GameObjectManager.Instance.backBuffer,null,false,false);
                myCanvas.graphics.drawRect(0,0,this.width,this.height);
                myCanvas.graphics.endFill();
            }
        }
        protected function startGameClicked(event.Event):void
        {
            currentState="Game"
        }
        protected function enterGame(event:Event):void
        {
            GameObjectManager.Instance.startup();
            inGame=true;
        }
        protected function exitGame(event:Event):void
        {
            inGame=false;
        }
    ]]>
    </mx:Script>
</mx:Application>

Package
{
    import mx.core.*;
    import mx.collections.*;
    import flash.display.*;
    public class GameObjectManager
    {
        public var backBuffer:BitmapData;
        public var clearColor:uint=0xFF0043AB;
        protected statci var instance:GameObjectManager = null;
        protected var lastFrame:Date;
        static public function get Instance():GameObjectManager
        {
            if(instacne == null)
                instance = new GameObjectManager();
                return instance;
        }
        public function GameObjectManager()
        {
            if(instance != null)
                throw new Error("Only one Singleton instance should be  instantiated");
                backBuffer = new BitmapData(Application.application.width,Application.application.height,false);
        }
        public function startup():void
        {
                lastFrame = new Data();
        }
        public function shutdown():void
        {
        }
        public function enterFrame():void
        {
            var thisFrame:Date=new Date();
            var seconds:Number=(thisFrame.getTime()-lastFrame.getTime())/1000.0;
            lastFrame = thisFrame;
            drawObjects();
        }
        protected function drawObjects():void
        {
            backBuffer.fillRect(backBuffer.rect,clearColor);
        }
    }
}