tried this on xbox 360 live arcade, cost 400 points (about 6$), has a 9x9 storyline/tutorial, playing locally and online.

not a bad introduction to go, though as I'm not a beginner I can't vouch for how instructive it would be. it is fun though and the AI has varying styles.

Only problems - a couple mistakes in problems where the solution requires the opponent to make a mistake. At one point I had 10 stones in atari but the AI just played damezumari to allow me to escape. I only noticed this in 2 problems, but they were quite obvious.

very few players in multiplayer and matchmaking isn't very robust (either friends or someone looking at the exact same time). It seems to account for escapers as I won a match by default after my opponent left.

at 6$, recommended as a tutorial and just for novelty.