This is one of those games , that captivates you ... but after a while is going boring
The hard part in this game is expanding your territories , because if you enter in war with a respected country , you will make much more enemies that you tough .
The ugly part in this game is unit control , you can only move your troops around the map only with a marshal . Hiring him it's not a easy job , you have to give 1000 gold at start and then wages of 10-100 , in function of number of marshals .
Every country have unique units , but you need resource to make them and here is the annoying part , you find horses only in certain parts of Europe such like the Balkans or the Central Europe ...
After my opinion the best country in game would be France , it's position grants many resources , many directions of conquering territories , etc.
I suggest you to play this game , enjoy it , but for a short time ...