I am a university professor, game developer, and 4X TBS game fanatic. I played, developed, collaborated on, play tested, analyzed, wrote about, and searched for 4X TBS games most of my life.
I played thousands of games and tens of thousands of hours of TBS games. I make this post after 300 hours of playing Old World. My estimated level of knowing and understanding Old World and its features: 60%.
Far from being perfect, but my perception is that Old World is currently the second best game out there. (I may be biased to 4X TBS, although I played many other genres).
Old World has the usual big problems with the UI: cumbersome, confusing, slow, buggy. Its AI seems to be somewhat better than the other 4X TBS AIs. As of today, 4X TBS AIs without exception are very poor based on my personal experience with hundreds of these games.
But Old World’s design is one of the best I have seen so far in any 4X TBS game. Finally, I see Order Points that limit the number of actions per turn and limit my movements. I advocated for this for 30 years in 4X TBS development. This game has great feature diversity, depth, and attention to details. Many things can be customized, even the music. I am yet to try the multiplayer. The developers genuinely understand and care about their product which combo is rare to find in the 4X TBS genre. This is not just another dumbed down “clone” of an earlier game that dominates the 4X TBS market today. They still push new patches which is great. This game is similar to Civilization 4, but much better. It also has tactical depth, role playing, and probabilistic planning, and a lot more. Kudos to the developers and I wish they will provide many years of support to fix the bugs, improve the UI, further tune the balance, and strengthen the AI to make the game even better than now.

This game cheats during combat. Making moves the player can't make.
The Computer always has 2,000 Shields, which allows it to Force March troops, even after spending all of those points to move troops or attack.
EVERY army the AI has, has a General in it.
The AI brings back Generals the next turn.
It's oppressive.
90% of the Events that happen are bad for you, or negative, or cause negative effects.
It's way too hard to be peaceful and ally with another nation.
No matter what you do, what tech you have, or how good you are with other AI players, they backstab you.
The Orders system is F'd, because you're restricted every turn, and you can't DO everything you need to do in your turn, like fight a war. If your king/queen has less Orders (moves) than the enemy and you have to fight a war, you're already dead. I hate it.
I've been trying to deal with this since I got the game, and have disliked it, and the further I get into a game, the worse it becomes. This ONE issue is enough to make me never play it again.

I've been spending up to 12 hours a day in this game for days now, and it's just stupidly overpowered against the player. Just when you start to get things right, the game sh_its on you. I had a few years of absolute peace, and building up my army and building up my cities, only to get absolutely rolled by the AI, who always had better tech, had more troops, and never ran out of Generals.
The movement across mountains, or using more Shield points than it should have to move troops is what did it for me.
I know the AI cheats in every game vs. Humans, but this is ridiculous.
F this game. It's got so many problems that Civ doesn't have. It's like they looked at Civ and went, "You know, how do we make the game way harder, and more difficult at the same time?... Oh, I know! We'll add families and traits, and negative events THAT NEVER STOP every turn so the player never wins..."
Also, this game will make your computer get really hot, max our your fans on your GPU, and has a conflict with Medal where it makes Medal tell you it's going to record the game every 5 min.
I had 2 cores heat up to 92c, which NEVER happens. And maxed out all of my P-Cores to min of 80c. (80-92c) That's insane!
I have a 13900K (Yes, I did the BIOS update to keep it from melting.) with a Lian Li 360 AIO running at full speed 100% of the time, and a total of 7 fans. 32GB of DDR5, and a 2080Super. I watch HWMointor because this game makes my computer a Space Heater. I watch voltages, I watch clock speeds on all cores, and I watch temperatures. No other game does this to my machine.
I don't know how people play this and are OK with it.
I'll probably uninstall.
Don't buy it. It's not what you think it is.
Just go play Civ and be happy.

Bought this in the run up to Civ 7, but i'm scared Civ won't be able to live up to Old World now. The best and most in depth 4X game on the market.