I suspect machine learning (and other, older ai techniques) might work for games - but one would probably have to train them for the right goal: fun. I suppose

I suspect machine learning (and other, older ai techniques) might work for games - but one would probably have to train them for the right goal: fun. I suppose for some players and some games, it makes sense to train for "good" - but even with chess - is it really fun to play an ai you cannot realistically beat - ever?