Go is an ancient Chinese game of strategy and territory about 100 times more complex than chess. While chess' best player is said to be a computer, there is still an uncollected 1 million dollar bounty for the first computer that can beat even a low ranked professional.
There exists dozens of programs, most aimed at higher level play as they are all there for experts to practice with, players to challenge themselves with or trying to code that million dollar winner. The few I've played aren't that hard to beat and have some serious logic issues, but then Go is not a game that can easily be broken down into code.
The Path of Go is aimed at beginners and newcomers to the game. Microsoft Research Cambridge last December released the game on the XBLA. It originally started as a research project into AI programing in 2004 it recently was turned into a retail product. Using the F# programing language and approximately 250,000 real life matches, they have succeeded at creating a credible and believable AI opponent aimed at beginners.
The game comes with a story mode along the lines of: a Go master sends you a letter telling you your twin is missing, you then embark on the "Path of Go" quest in order to find him/her. The game also has local and online matches against AI and real life opponents. Unlike the traditional board game that uses a 19×19 intersection board, The Path of Go uses the much smaller and much simpler 9×9 board for it's matches. As a casual player myself I can attest that smaller boards are better for introducing new players to the game. The larger board really is like being thrown into the deep end.
The game uses Xbox Live Avatars and retails on the XBLA for $5 (400MSP).