Move your mouse to rotate the square. It will rotate based on the distance between the square and the mouse-pointer. Hold down space to move the square. Press 'd' for trail. Press 'f' for no trail. Press 'r' to reset position. Press 'c' to clear pen. Hold down 'g' to make the square follow your mouse.
A thing that I made for fun. If you press space and 'g' at the same time, while moving your mouse around, it will look really cool. A fun challenge would be to keep the square from hitting the edge! (Without pressing 'g', of course.)
