Tic Tac Toe

Do you remember the classic game of Tic Tac Toe? You can play it now, against a friend or against the computer. The mechanism is pretty simple. You have a board with nine squares and you have to click on one to add your symbol to it. Every player gets a turn to place its symbol and the goal is to make a line of three of your own symbol before your opponent does. The line can be vertical, horizontal or diagonal. But as you try to make your own line, the opponent will try to do the same, so you will have to trick him as well as to stop him at the same time. In the bottom part of the screen you can see who's turn it is as well as what is the score. There are four levels of the game which just tell you the difficulty of it. So can you be the winner? Good luck!