I've played many games like this. Games like this seem to confuse "difficult" with "cluster-♥♥♥♥".
The game throws out notifications all over your screen before you even know what is going on, and even then it is difficult to ascertain what it is trying to convey. The UI is not even remotely intuitive. The AI makes decisions that make no sense at all. Controlling anything is totally unintuitive.
This game is perfect for people who like to feel superior to others because they spent the time fighting the design, rather than playing the game. You can actually lose before you even started getting into things and then lose over and over again after having your first ruler die because they could not produce offspring. There is nothing you can really do to control this besides going "please respond" to every ruler on the map when looking for a wife. Even then, you can screw yourself. Not like it matters since your ruler will start to gain vices for no explicit reason, impairing his or her ability to rule. Again, you have NO CONTROL over what happens.
You want to simulate the trait rolls in this game? (DO NOT ACTUALLY DO THIS DO NOT ACTUALLY DO THIS YOU WILL DIE DO NOT ACTUALLY DO THIS) Get a jar of used medical syringes and some rusty nails you found on the side of a construction site. Smash them on the ground and roll around and see what kills you. It does not really matter, but it's an accurate depiction of what it is like being a character in this game. (DO NOT ACTUALLY DO THIS DO NOT ACTUALLY DO THIS YOU IDIOT DO NOT ACTUALLY DO THIS)
Just get CKII. There is much more to do and it's just as "difficult" without being as obtuse. You won't have to deal with the resolution issues either.
Still, if you absolutely love these types of games, I suppose you can get this one.
Also, it's pronounced "DOMAIN", not "DEEMEENZEE".