Anyway, what I liked:
Everything to do with the character system. Every character has traits and skills. Skills are like CK2's attributes, except they grow as a character does his jobs, and there's no learning or tech growth. Traits affect relations, but more importantly happiness. Happiness is pretty important, giving a bonus to everything a character does. And things you do that affect someone else's happiness also affect your relations. People like you when you do things that make them happy, and also when you do good things for their friends. An example of all this: On my first game my medical councilor was Proud and untalented at being a medic. As a result she hated her job and she was miserable. One of my vassals was her friend, and he hated my guts because every single trait we had was incompatible and I was making his friend unhappy. I later switched her to a different council position and gave her a husband she loved, she became happy, and my vassal (barely) stopped hating me without me doing anything for him directly.
The game also has a grievances and favors system that are generated by various things you do.And they can cancel each other out, giving a nice sense of "eye for an eye" and escalating vendettas. For example, you can ask any of your vassals for money. It normally generates a grievance, but if the vassal has previously given you a grievance (by refusing a call to arms, for instance) then the grievances cancel each other and the matter is considered settled. Unless you opt for a punishment more severe than the crime, at which point not all grievances are cancelled, and the matter may gradually escalate.
Secrets. Not everything is public knowledge. Everything clandestine starts as a secret that can be discovered. For example, I had an affair with one of my vassals. In the beginning it was a secret and everything was fine. But then people found out, my wife hated me, and I got a bad reputation for being dishonorable towards her.
Action points. Every turn you get a number of action points depending on your happiness. Everything you do requires various amounts of action points, from arranging a marriage to attacking a system. You, theoretically, can't do everything you want to do each turn.
What I disliked:
The economy is practically nonexistent. Every system has an econ rating, current and maximum eg 50/60. You can invest to increase the current rating, up to the max, but there's nothing you can do to increase the max. Your system's economy affects your taxes, the size of your personal fleet, and the maximum size your house can be before it starts generating unrest. And that's about it.
Military is similarly simple. You have your personal forces and your vassal forces. Vassals cannot support their forces too far from their homes. You don't move your fleets directly. Instead when you click to attack a system, you automatically gather all available fleets in range, (unless a vassal refuses which generates grievances), the defender does the same, and you fight it out immediately. Admirals give bonuses and can generate events that affect the battle, but otherwise raw numbers are used to generate the odds of victory and the larger force generally wins. You cannot improve your fleets' quality, morale or even composition. It's all just raw numbers.
There's not enough to do at peace time. After a while I kept ending turns with half my action points unspent.
The world is too static. You cannot colonize new systems. Existing systems will max out their economy shortly after galaxy creation, and remain that way for the entire game. Economy decays a bit every turn, but not enough to affect anything. And there is no technology progression, no progression at all actually. Nothing to differentiate factions at all.