Once you press the green flag, the art should appear -=- This is an easy demonstration on what is called Parallax. It involves moving different things in different intensities, creating the illusion of depth. As you move the mouse, you can tell different layers of the artwork move in different speeds, creating a distinction between the "foreground", the "middle ground" and the "background". This concept can be - and has been - extended to make many different horizons.
