Well, I can't get the applet to work on an html... only on the applet Viewer on NetBeans. Perhaps there's something wrong with the dir to the resources?

   public static final String Texture_LightPlayerPiece = "/data/marble.jpg";
   public static final String Texture_DarkPlayerPiece = "/data/wood.jpg";

texMan.addTexture("LightPlayerPiece", new Texture(documentBase, Resources.Texture_LightPlayerPiece));
       texMan.addTexture("DarkPlayerPiece", new Texture(documentBase, Resources.Texture_DarkPlayerPiece));