Firstly, when you attack any nation, your own people revolt against you despite raising stability, etc.
Not very realistic is it?
Secondly, why is the mercenary training same time queue as training from your own province manpower? It should be instant like Crusader Kings.
Thirdly, same problem as all Paradox strategy games, messages pop up out of no where and mess up your screen when you are trying to do something else. Too much spam.
I can go on fourth, fifth, sixth, maybe reach tenth, but people should try it before they judge. I tried all Europa series, this is better than the previous but still fail.
Overall, crusader Kings were better series in development, and I hope the creators hire professional designers next time to reach the standard level of Total War series, then the challenge between both games can be called.