I'm not a go person, and honestly don't really know how to play. I put the cube way small, and had some fun games with the AI! I think starting on the 3x3 would overwhelm less players from the start, even though the 6x6 does look more impressive.
If you wanted to add more features, a replay feature would be cool, especially if you could pause, rewind, move the board around ETC.
And this is very weird, but I feel like this would be 1000% times better in VR. Just a crazy idea.