Tic-tac-toe in C# This is a simple tic-tac-toe game with the sole purpose to practice C# and learn about WinForms. You can play it against a second player on the same computer, or play against the CPU. How to play Select the playing mode, and choose to play against the cpu or a 2nd player on the same pc. Press the toss a coin button to see who goes first. The top banner will indicate which player goes first. Whoever can get the symbol in a consecutive row (including diagonals) wins the game. You can press the reset button to play again.