Reasons why you shouldn't buy this game:

Check facts: Look at achievements. Only about 3% of people were able to finish the game.
95% people actually start it. That's extremly high. So people who buy, want to play it. It's a niche game so it's understandable. 40% people get immediately put off by super-early game. Only 33% make it to the moon. 13% build a rather small fleet of 10 ships (Aliens attack with 60+ ships in fleets easily). Around 5% people make it to the Jupiter, which is supposed to be a frontier between you and Aliens. And about half of that makes it to the win.

The game is EXTREMELY unfriendly to the beginner. It's full of unexplained or poorly explained mechanics, traps and really different concepts.
From what I have seen and heard is that devs are following a few elite gamers and the cycle goes like this: The game was supposedly fun in the beginning. Then some players (naturally) got their strategies so perfected, they finished the game with ease. Devs probably hated it or maybe took is a personal insult and the result was they nerfed the ways that the nerds found. Nerds found other way to break the game. Devs bashed with their nerf hammers. This cycle continued and you are walking into a strange land where lot of things don't work and most of the tech tree is filled with useless techs, that are at present either full player traps or are marginally useful in niche cases. Of course you don't know which ones are which.

Example. Out of many weapon tech categories, you can say this:
Lasers - Useful at short range.
Magnetic weapons - Useful at capital ships. Need to have enough to get though the enemy PD.
Missiles - Used to work early game. From the reports I have read and from what I have seen, nerfed to the ground.
Nukes - Like missiles but worse. Ever saw your whole barrage of deadly nukes vaporized by one enemy lazer in an epic chain reaction?
Antimatter topedoes - Useless.
Antimatter beam - Useless.
Plasma weapons - Nerfed to ground.
Did I forget something? Not sure. Anyway out of what? 30 techs? Dedicated to weapons, you'll use laser PD with either laser nose cannon or coil nose cannon.

How many drives are there on the tech tree? 40? 50? How many you should use? Starting for Earth defense, maybe one long rage, then universal, and then maybe one on the way to the top tier and one top tier. Do you know which ones you want/need? Let me tell you: No, you don't. You don't have a clue about why there are so many engines and what they do. You have no clue what the stats on them mean. What is good, bad and what you should want and aim for.

Space battles: Given the UI and and the controls you have, you are not meant to actually manually play them. It's possible, sure, but doing anything but High Wall + last stand turrets is shooting yourself into the leg because enemy is way faster, way more armored, way more everything. Your ships are slow, cumbersome, poorly armored and either can't hit the fast moving enemy or completely ineffective. The only thing they still can do is turn around. In lategame, sure, go ahead and try something. But you won't get there most likely. You'll probably have to wait like 300+ of your play hours to see the endgame.

Alien hate meter. You are briefly told about it (if you caught this piece of information amid the flood of new/foreign concepts). Well, this is probably the worst and most important part of the game. Especially for the beginner. You have some idea that is has something to do with vague alien threat. Then an alien fleet will arrive and wipe your space assets. Because you didn't know exactly what is happening and what to do. Get ready to do some googling, get exact numbers and then play by them. Congratulations, now you are part of the "skilled" ones.

Did you just start? Do you like the game? Great. Oh, you didn't go for one of the three or four possible best starts? Bad luck, you should have Googled. Now you are way behind and it's better to restart because you won't be able to make it until secret deadlines that... ...well let me not spoil it for you completely. Let's just say you are screwed. Ok, so you skillfully grabbed one of the few chosen starts? Good. I hope you grabbed those countries that will enable to win the race to moon and prioritized boost heavily in those (usually economically wrecked) countries you had. Ooooh... You didn't? How should I tell this... Well, you know the game is actually not about what you were presented and what you are playing. It's not about that Earth you are playing on. You need to grab those special countries that give you boost so that you can get the best spots on the Moon. You know, because if you don't, your whole game is basically crippled. With leftovers on Moon, the game becomes much harder, because you were meant to grab those sweet spots and use them to venture forth into the space. And then there are races to other places. Mostly for reasons that became apparent 150+ hours later into the game.

My point is. if you want to be among the 3% of the people who finish the game, you have to follow a certain path. That path is rather narrow and very well defined. Some elite players will be able to stray from it because they know every corner of the game. You don't. You stray from it, you lose.

Ship designer becomes remotely interesting, but mostly you are trying out ship designs and settle on some of the few chosen builds eventually. Spoiler: Laser ships, coil ships, (no, missiles don't work even early game anymore), (no, that doesn't work either), (sorry, nerfed this), (lolz, you serious), colony ships (You didn't know, did you? I hope you accidentally beelined to the needed techs and know where and how to get to the new frontiers.), possibly marine ships. Time jump to late midgame: Dreadnaughts, Lancers and Titans.
I think there is huge missed opportunity with smaller ships here. The power jump between classes is huge and you are constrained by mission contol points so it's almost always best to build the biggest ships as two ships for 2MC apiece are not even remtely as powerful as one 4MC ship. Barring some weird edge cases.

Ever dreamt of waiting 6 seconds each time you open a tech tree?

Ever tried to manage stations and colonies with UI that randomly loses your previous list? So you need to start over again and again? Try managing 50 of them when you get a new power plant tech. Oh, and the list reorders reversely each time you reopen it.

Please, can you record the moment you first decide to send a ship somehwere? Please send me the video of your face when you try to figure out the travel system for the first time.

This game could have been great. Alas, it's not. It's a tale of bad UI and nerfing the fun out of the game. Honestly, I can't comprehend how the developers play their own game. The UI is a PAIN to use. Another example: Did you know when you have 2+ groups of ships in combat and if you press the number of another group too soon, you battle view will completely reset and center point blank to a ship in the group? You should have waited until the rectangle animation finishes. Nobody told you? Oh, well, just zoom out, rotate, move, zoom in rotate aga- oh, ... you pressed it too fast again? Daaaaamn...

Terra Invicta is a honeymoon game, a game that is incredibly compelling and engaging in the beginning as you're learning it. You'll set goals during the honeymoon phase, but once you hit the normal phase and see the game for what it is, you're going to suffer no end of frustration in figuring out the obtuse mechanics for achieving your player-set goals. To put it plainly, the game does a terrible job of telling you how to do things. This game attempts to have extreme depth, but interacting with that depth is neither intuitive, nor well tutorialized, and this incompetence on the developer's side leads to player frustration.

The answer to most of your problems will be to "go to the wiki" to figure it out. Go to reddit or some forum somewhere and ask. If you like that, then great, but if you remember when games actually explained themselves, you likely find that to be unacceptable.

Want to merge nations? Cool, you can do it peacefully or be a warmonger. You want to do it peacefully? Cool, that's called unification. How do you unify? You send a counselor and set the policy. Cool. How do you make the unification policy even show up? Who knows. You can federate, too! How do you federate? Have two nations with claims on each other and send a counselor. Awesome. How do you set claims? No idea. The game fails to explain any of this or locks this behind the tech tree.

In short, you'll eventually run into a point where the game is just frustrating, and then you'll drop it for something made by more competent developers.

Very likely a good game that I can't recommend to anyone.

This game is unlike any other game currently on the market. It combines geopolitics, ship design, resource management, research, and so much more in a way that no competitor comes even close to. From what I understand, the developers were also in charge of the Long War mod for XCOM, and yeah that fits perfectly.

This is the perfect game for someone like me. I love to research the meta, invest a ton of time into learning strategies and optimal play styles, watching Youtube playthroughs and reading the discord, and learning from my mistakes. The problem is I would never recommend this to any of my friends, and to anyone who just wants to sit back and have fun. This is a simulation, not a game.

You can spend 20-30 hours on a campaign just to find out that a decision you made 10 hours ago screwed you over. Your first campaign will be a trial run. There are loads of other reviews pointing out the various game design problems, such as the UI, the balancing philosophy of the devs, and insanely steep learning curve, but my biggest complaint its how many clicks you need to accomplish basic tasks which you will have to do over and over and over again. Basic tasks like moving armies require way too many actions to accomplish. This is made doubly worse by the lag the game experiences due to the aliens having 500 ships divided among 100 different fleets. By the middle-late game you will fight the UX more than the aliens.

I am greatly looking forward to future updates, and I sincerely think the devs have created something truly unique, but at this moment I cannot recommend the game to the average joe.