Four in Line - Overview

This game is playable against the computer. You play with the 'O' sign, and the computer plays with the 'X' sign. The purpose is to make 4 consecutive signs of your own, on the same line, column, or diagonally.

A move consists in placing your own sign on one of those 13 columns, at your choice. The sign will fall down towards the base of the column, until it reaches another sign. Due to this, the columns will be filled bottom-up.