Very good strategy game but not for casual players.
The secret and downfall of this game is keeping your vassals happy. If you keep them happy you can sit and build up your Counties, Duchies, Kingdom peacfully or can go to war with the strength of your vassals armies. But if your vassals are unhappy then this game becomes tiresome very quickly with having to quell numerous rebellions which come at inconvenient times (during a foreign invasion). When your kingdom gets large enough it gets to be too difficult to keep everyone happy and you end up spending all of your time trying to keep your vassals in line. This game is fun for building up a small county into a moderately sized kingdom (ex. County of Rama into the Kingdom of Croatia.)
Overall a good game but not for the casual gamer. This game takes a while to get the hang of and will take numerous hours of gameplay to get through.