Slurdge.org

To install the game, just run the setup. The music version is bundled with Hikaru no Go music, so I believe you must not download it if you do not own the Hikaru no Go soundtrack. In this case, just download the version without music.
To play, run the game and select options from the menu. From then, it's the classic 4x4 game, in which each player plays in turn. You can select computer play in the option, and adjust the strength of the A.I.. The harder A.I. is very difficult to beat ! The whole game plays with the mouse.