anchor.diff:      _sounds['laser'].load(),
     ]);
   
  +  await Future.wait(loads);
  +
  +  // TODO(eseidel): These load in serial which is bad for startup!
  +  String json = await _bundle.loadString('assets/sprites.json');
  +  _spriteSheet = new SpriteSheet(_imageMap['assets/sprites.png'], json);
  +
  +  json = await _bundle.loadString('assets/game_ui.json');
  +  _spriteSheetUI = new SpriteSheet(_imageMap['assets/game_ui.png'], json);
  +
  +  _app = new GameDemoApp();
  +
  +  assert(_spriteSheet.image != null);
  +
     SoundTrackPlayer stPlayer = SoundTrackPlayer.sharedInstance();
     SoundTrack music = await stPlayer.load(_bundle.load('assets/temp_music.aac'));
     stPlayer.play(music);
   
  -  await Future.wait(loads);
     runApp(_app);
   }
   
  
positive.code:     sprtBackground.position = new Point(512.0, 512.0);
      addChild(sprtBackground);
  
      StarField starField = new StarField(_spriteSheet, 200, true);
      addChild(starField);
    }
  
negative.code:     'assets/game_ui.png',
    ]));
  
    // TODO(eseidel): SoundEffect doesn't really do anything except hold a future.
    _sounds['explosion'] = new SoundEffect(_bundle.load('assets/explosion.wav'));
    _sounds['laser'] = new SoundEffect(_bundle.load('assets/laser.wav'));
  