TL;DR: Terra Invicta feels like an abusive relationship: It keeps disappointing me and I desperately want it to be something it's not, but I keep sticking with it because I think that if I keep at it just a little longer it'll finally realize that potential that I really want to believe it has.

But to be more specific...
WHAT I LIKE:
-The idea that tribalistic infighting over how to address an alien invasion being as much of a problem as the aliens themselves is SO clever, and the tension feels real and earned.
-The music is appropriately atmospheric.
-Issues with the progression aside (more on that in a bit), there IS a constant feeling of both vertical and horizontal progression that's pretty satisfying.
-Some of the voice actors (The standouts to me are Hanse Castillo, Khalid al-Ashgar, and Judith Howell) are phenomenal.
-The Initiative is so moustache-twirlingly evil that I absolutely love to hate the guys.
-The simulation is detailed and thorough and almost nothing feels like it's bad because of laziness or lack of care. If the eccentricities of this game seem like your jam, it does well at scratching those very eccentric itches.

WHAT I DON'T LIKE: THE GENERAL:
-The game has four separate event notification systems. None of them individually work well, and all of them together are less than the sum of their parts.
-The UI is kind of a mess, and a 4X/Grand Strategy game is its UI.
-It doesn't teach or explain its systems well, and some of these systems don't even start to unlock until dozens of hours into the game. I love learning by experimenting, and this very much feels like a game where wiki deep-dives and watching videos of other people playing are the ways to learn it. For me, personally, that feels counter to why I want to play games like this in the first place.

WHAT I DON'T LIKE: THE MORE SPECIFIC:
-Managing councilors feels a little bit tedious when it's the main game mechanic, and a LOT tedious once you start managing later-game systems.
-It's detailed and thorough in ways that actively harm it. For example, though you're constantly unlocking warship technology from almost the start of the game, you have to wade through piles of tech that are first wildly uneconomical, then so weak as to be useless, before you get to something even baseline practical that I don't understand why they didn't just push shipyards back and cut out all those earlier techs.
-Your faction determines the entire course of your objectives in the campaign, but you're not given enough info up front to make an informed decision about which one you want. For example, I get that the Servants are zealots and the Protectorate are good ol' fashioned cowards, but without getting 30 hours deep into each of their campaigns I don't think I could tell you why their goals are even a little incompatible. Likewise, at a glance, Humanity First just feels like a grumpier Resistance with a red coat of paint.

WHAT I DON'T LIKE: THE EXTREMELY PETTY:
-Fiona Ayoade, the advisor for the Resistance, the only faction that makes any effort to teach you how the game works. I find her deeply, viscerally unpleasant in a way that none of the other advisors come close to. The worst I can say about my next-least-favorite advisor (Kiran) is that he just kinda seems like a boring muppet.

I REALLY want to like this game, and I know it's going to pull me back in at some point. Maybe I'll suddenly find that I love it when that happens! But right now, all I see is promise buried under mountains of tedium and an almost malicious disregard for the player's time that I would caution almost anyone from even starting it.