In this classic game, two players take turns dropping counters into a grid.
You play with red counters and your opponent plays with yellow. You can choose whether your opponent is the computer player or a friend.
The aim of the game is to get four of your colour counters in a row. They can be in any direction - horizontal, vertical or diagonally up and down.
Easy to learn but with hidden complexity, this is a game of strategy and planning.