I already understood most of the basic things, but a lot of obscure options remain hidden. For example, I managed to catch from the safety code that if you police the realm you are less likely to lose your money in the black market. That kind of thing can only be found in the manual, and I am sure that a lot of such options are simply "hidden" from us at the moment.
I played a game based on offense (which is
really not my style) and I managed to grab half of the map with the only other King as my ally at 9. Then the option to "claim" appeared and I had no idea what that was. It failed and the other king claimed the Kingship of England for him and I lost.
Again, stupid option that I had no clue about led me to defeat...
I think I prefer Castle instead of Castle 2. At least you had the advantage when defending. And it was more interesting to build your castle back then, which should be the main part of the game (but is not anymore).