Click the buttons at the top of the screen (or use the corresponding number keys) to change the color of the top left glob. If two globs are side by side or on top of one another they will merge into one glob.
Make the entire play field the same color in 25 moves or less to continue playing and go for an extremely high score!
UPDATE10/30/08 : Fixed an issue with scoring that caused some extremely high scores not to count. Now players will score much lower scores on average but they will pass correctly.