text: game.TitleScreen = me.ScreenObject.extend({
      init: function(){
          this._super(me.ScreenObject, 'init');
          this.font = null;
          this.ground1 = null;
          this.ground2 = null;
          this.logo = null;
      },
  
      onResetEvent: function() {
          me.audio.stop("theme");
          game.data.newHiScore = false;
  
          me.game.world.addChild(new BackgroundLayer('bg', 1));
          me.input.bindKey(me.input.KEY.ENTER, "enter", true);
          me.input.bindKey(me.input.KEY.SPACE, "enter", true);
          me.input.bindPointer(me.input.mouse.LEFT, me.input.KEY.ENTER);
  
          this.handler = me.event.subscribe(me.event.KEYDOWN, function (action, keyCode, edge) {
              if (action === "enter") {
                  me.state.change(me.state.PLAY);
              }
          });
  
          //logo
          var logoImg = me.loader.getImage('logo');
          this.logo = new me.Sprite(
              me.game.viewport.width/2 - 170,
              -logoImg,
              {image: logoImg}
          );
          me.game.world.addChild(this.logo, 10);
  
          var that = this;
          var logoTween = me.pool.pull("me.Tween", this.logo.pos)
              .to({y: me.game.viewport.height/2 - 100}, 1000)
              .easing(me.Tween.Easing.Exponential.InOut).start();
  
          this.ground1 = me.pool.pull("ground", 0, me.video.renderer.getHeight() - 96);
          this.ground2 = me.pool.pull("ground", me.video.renderer.getWidth(),
                                      me.video.renderer.getHeight() - 96);
          me.game.world.addChild(this.ground1, 11);
          me.game.world.addChild(this.ground2, 11);
  
          me.game.world.addChild(new (me.Renderable.extend ({
              // constructor
              init: function() {
                  // size does not matter, it's just to avoid having a zero size
                  // renderable
                  this._super(me.Renderable, 'init', [0, 0, 100, 100]);
                  this.text = me.device.touch ? 'Tap to start' : 'PRESS SPACE OR CLICK LEFT MOUSE BUTTON TO START \n\t\t\t\t\t\t\t\t\t\t\tPRESS "M" TO MUTE SOUND';
                  this.font = new me.Font('gamefont', 20, '#000');
              },
              draw: function (renderer) {
                  var measure = this.font.measureText(renderer, this.text);
                  var xpos = me.game.viewport.width/2 - measure.width/2;
                  var ypos = me.game.viewport.height/2 + 50;
                  this.font.draw(renderer, this.text, xpos, ypos);
              }
          })), 12);
      },
  
      onDestroyEvent: function() {
          // unregister the event
          me.event.unsubscribe(this.handler);
          me.input.unbindKey(me.input.KEY.ENTER);
          me.input.unbindKey(me.input.KEY.SPACE);
          me.input.unbindPointer(me.input.mouse.LEFT);
          this.ground1 = null;
          this.ground2 = null;
          me.game.world.removeChild(this.logo);
          this.logo = null;
      }
  });
  