Turn on your control sound. Click the purple sphere to hear voice and move it further towards blue box with each click.
Click the green sphere to change background colour to yellow and it too moves accordingly inwards towards the blue box.
Click right hand button on the green sphere for it to move side to side and go into the distance. See how far into the distance you can get it, clicking alternately on the purple one until hidden in the box. Click refresh/reload to return to normal