The yellow box is the one you are currently on. Press one of the arrow keys, and if you get the right one, it will turn black, if you get the wrong one, it will turn red. The difficulty ranges from 1 to 5. You have 3 times the number of boxes for your moves left (top left). Your score is the number of black boxes when you run out of moves left.
It is kinda impossible to get a perfect score unless you cheat. Comment your score and difficulty.
