Just like any tic-tac-toe game you click where you want to go and your "X" will appear there. You are the "Xs." If the "X" doesn't appear then hit the green flag, also that will restart the game. if the computer loses then post it in the comments. Also post the sequence you used to do it.
It took a long time but I finally made the computer "invincible" with the help of my amazing father. :P
