Capture as much area as you can, but do not let the nasty floating square touch your green trail, or you must start over.
Move with the keyboard arrow keys.
If the keys do not seem to work, click the mouse inside the applet.
To win, cover a lot of area.
Then you will have created a stunning, if impermanent, work of modern art!

Press Enter to start a new game.
To win more games, cover more and more area.