That would be funny. The difficulty slider changes to "How many hours of playtime" instead of easy, medium, hard. Actually it could even just scale it automatically based on a metric like steam hours played. that would be awesome.

I don't think so. Many of the fun things AIs do in games is attack at different stages of the game. They send a small force at the beginning, and then a little larger force a few minutes later, and then a big attack at the end. No AI trying to win would end up at this strategy. You would have to define the fun goals and have the AI train on that for it's success criteria.