Use the arrow keys to move the paintbrush (the ball) around. However, the paintbrush will continue to move in a straight line until it hits a wall. Paint over all the grey squares to finish the level. Finish all the levels to complete the game. Enjoy! There are 25 levels. Some levels are harder than others, but they are all solvable. I have played the game from start to finish without touching the code.
If the paintbrush gets stuck where it won't move but is not supposed to be touching a wall, please let me know what level and where in the comments. You can see what level it is on the home screen. Try resetting the level, and if that doesn't work, go home and back again.
