It's by Paradox, with all the good and bad that implies, but it's definitely as good as anything they've ever done.
It's not really a traditional strategy game in the use resources/build armies/conquer vein. It shifts the focus to basically being a dynastic simulator, where you play as a succession of rulers over many generations (hopefully...if you leave no heir the game is over).
It's much more about palace intrigue, diplomacy, religion and even role playing. In true Paradox fashion, there are countless details that make a rich and dynamic game world. Also in true Paradox fashion, the interface alternates between intuitive brilliance and clunky frustration. Totally worth it for me though.
So far I've only played about 30 years. My "starter" king, the King of Croatia finally had a son in his twilight years. The young heir was only 3 when the King died, so now I have to deal with a regency. Naturally, every landed noble great and small sees this as a chance to take advantage. My dungeons are doing brisk business.
If anyone's interested, there is a cool thread at GWJ that shows what the game can do.
http://www.gamerswithjobs.com/node/110907?page=6
This screencap really says it all about this game
