The buzz on that is it's basically a war game where you build up a big army and then fight. Not interesting to me.
Of course this was awhile back, maybe they've updated it? Or is it still a slog to see who can build the biggest army?
They have a decent amount of ways to adjust the AI to make it less aggressive.
They also have a 'make your goals' victory (essentially imagine a series of more-elaborate CS quests to complete) that can be non-militaristic.
I'd roughly say, if you want a competitive experience/challenging AI you definitely need a big army and fighting. If you want to play on easier levels, you can get away a lot less without.