text: game.PlayScreen = me.ScreenObject.extend({
    init: function() {
      me.audio.play("theme", true);
      // lower audio volume on firefox browser
      var vol = me.device.ua.contains("Firefox") ? 0.3 : 0.5;
      me.audio.setVolume(vol);
      this.parent(this);
    },
  
    onResetEvent: function() {
      me.audio.stop("theme");
      if (!game.data.muted){
        me.audio.play("theme", true);
      }
  
      me.input.bindKey(me.input.KEY.SPACE, "fly", true);
      game.data.score = 0;
      game.data.steps = 0;
      game.data.start = false;
      game.data.newHiscore = false;
  
      me.game.world.addChild(new BackgroundLayer('bg', 1));
  
      this.ground = new TheGround();
      me.game.world.addChild(this.ground, 11);
  
      this.HUD = new game.HUD.Container();
      me.game.world.addChild(this.HUD);
  
      this.bird = me.pool.pull("clumsy", 60, me.game.viewport.height/2 - 100);
      me.game.world.addChild(this.bird, 10);
  
      //inputs
      me.input.bindPointer(me.input.mouse.LEFT, me.input.KEY.SPACE);
  
      this.getReady = new me.SpriteObject(
        me.video.getWidth()/2 - 200,
        me.video.getHeight()/2 - 100,
        me.loader.getImage('getready')
      );
      me.game.world.addChild(this.getReady, 11);
  
      var fadeOut = new me.Tween(this.getReady).to({alpha: 0}, 2000)
        .easing(me.Tween.Easing.Linear.None)
        .onComplete(function() {
              game.data.start = true;
              me.game.world.addChild(new PipeGenerator(), 0);
         }).start();
    },
  
    onDestroyEvent: function() {
      me.audio.stopTrack('theme');
      // free the stored instance
      this.HUD = null;
      this.bird = null;
      me.input.unbindKey(me.input.KEY.SPACE);
      me.input.unbindPointer(me.input.mouse.LEFT);
    }
  });
  