Well, I will try to explain what went wrong for me with this release.
I watched Imperator pretty closly, read every dev diary and watched the dev clash. So, I knew what would be in the game, and the dev clash showed what I should expect - but as it turns out, it showed ALL that I could expect, and nothing more. Let me try to explain.
Families are in the game. They are also utterly unimportant. I thought we were only getting glimpses of family interactions in the dev clash, because the commentators made a big deal out of the family feature, and how people would plot, and you could have enemies and friends, and it is important to keep families happy, or else ... And thats all true, at a surface level. But what that system is, is "Alert in the top right corner, click one button, forget it". Thats literally all there is to families. At least it feels like it when playing the game. I didn't have any concrete expectations what would happen with families, but since it was so prominently featured (with detailed character models, lineages, and so forth) I expected something interesting. Instead it is boring.
A big deal was made out of civilization level. There were contest between players, who could achieve the highest civilization level, and the commentators commented on it regularily. Yet, as I played the game, it turns out that civ level is absolutely trivial to achieve and does nothing beyond adding a buff. Or something. I don't even really know what it does off the top of my head, but it feels like it has no impact at all. It is literally just a number, and in my first playthrough I played neither tall nor especially focused on tech or civ level, yet my barbarian german nation has a higher civ level than Rome in some province in the middle of nowhere. So... huh. Disappointing.
Pops were mentioned, with the added "... just like victoria" which I knew not to be true, because the numbers were abstract instead of real population size, but I expected them to not be completely static without my intervention. It is just development from EUIV with another name, and instead of changing a whole province to a new religion or culture, you change it in increments. Only one pop can grow in a proivince (randomly?) and population management is just pointless once you are bigger than 15 cities or so. It's also a clickfest. Again, don't know what I expected, but at least something.
To try to some it all up: The dev clash made it look like you'd have some goal or sense of achievement in the game, but that was literally all roleplaying by the players and commentators. Watching the game was fun, playing it is just boring (I am only playing singleplayer). Diplomacy is bare-bones, peace-time gameplay is waiting to click an Omen and building roads (which I actually enjoyed thoroughly), and war is no fun either. I did not expect much, anyways, because paradox combat is always pretty hands off beyond "coax the AI to attack you in a disatvantageous position or just throw numbers at the problem" but the forts take soooo long to siege down that it is just a waiting game. It is also incredibly easy to blob, the only danger to me was Rome because they get so many buffs and bonuses, but once your country reaches a certain size, wars just become tedious - as was apparent in the dev clash already, where Rome was attacked on all sides constantly yet nothing was achieved. In short, the game has no single thing that's fun enough to keep you occupied. Everything is just "meh" which is not good. I get it, Paradox Games grow over time, but Stellaris for example, the only other title I played at launch, at least had enough interesting stuff to keep me playing. I've played for maybe 20 hours (of which at least 5 must have been waiting) and I think I've seen all this game has to offer, and I have no desire to play it again anytime soon. I only played so long to finish a playthrough, to see what would happen in the late game and the end of the game, but nothing happened. It felt like wasted time.
So, tldr: Dev Diaries and Dev Clash made the game look fun, but it isn't. It's mostly waiting (for power to press a button or for sieges to finish) or a chore (micromanaging things just for the sake of it because there is nothing else to do while waiting for mana).