To preface, I love this game but I can't really recommend it.

Okay, Pros to start with:
Most of the game is fun.
Designing ships is fun and addicting.
The game mods are great, N.A.R. added new nations to play as for example.
It's very easy to start up and lose a few hours because you keep telling yourself "just one more turn/design/battle."
*Still has potential to be great if modders could take over like with Bethesda games,

The cons:
Bugs, lots of bugs, many of which have been here since early access as many have attested to and others that keep coming back whenever they're squashed.
Horribly optimized in areas like the tabs players will typically be switching between in campaign.
Horrible UI elements, some (like the Log on the Campaign Map) are useless.
The campaign map doesn't wrap, there's not even a button or something to switch from one side of the map to the other, you have a massive black border that hides some islands in the Pacific, the map makes fighting in the Pacific hell for ALL the wrong reasons, the mini-map made things slightly better but it's still terrible.
Features have been removed, for example originally allies would join wars but that was removed around 1.4 and until 1.6 you could have the AI take command of your ships during battles and this was sometimes necessary to get ships moving because of a bug that renders them actually brain dead upon loading into a battle.
Designs can become broken because of advancing tech levels in the campaign because the game forces things like new gun turrets onto the player whenever they're researched and at the start of V1.6 there WAS a promise of letting the player's chose the turret style they want but that was since removed from the list of features (I saw one person say it may have been permanently removed) so be prepared to have to change a LOT of things if you make a refit of a ship after going from Mark 4 to Mark 5 turrets or something.
Be careful when posting in the forums, you can and most likely will be banned for reasons like this: https://imgur.com/a/KeKrNOz
The developer has talked about restricting the core features of this game as shown here "In the end, what we should really do would be to disallow so much freedom on placing funnels, to prevent the unrealistic and ugly looking ships that some players want to make to minimize weight offsets. What happened is that weights are more accurately and strictly measured, so it is more demanding to design a ship, which previously could be more easily become over gunned, too fast, and generally overpowered." (Post Link: https://forum.game-labs.net/topic/44058-v16-feedback/?do=findComment&comment=787232 Archival Screenshot: https://imgur.com/a/t1NYJVf taken on 9/3/24) So there is the very real and present possibility of losing basic features that have been in the game for a while.
The developers have nerfed a lot of things into the sea like accuracy and of course the most recent ATROCIOUS Fore Weight Offset which resulted in some pushback and said offset is the reason for player's making "unrealistic and ugly looking ships" to have some form of stability.
Feedback, even something as frequently requested like "add buttons to turn off Mines and/or Subs"is very likely to be ignored and the many people asking for a better campaign UI and map have definitely been ignored.
Developer exhibits highly unprofessional and even hostile behaviors for the weirdest of reasons and at the weirdest of times (as in the reason I am now perma-banned form the forums here) both here on Steam and on the Game-Labs forums, many of the other Negative reviews for this game point out this too. Just filter by Most Helpful (All Time) and the top second one has multiple examples of this.
Multiplayer is a DLC that is just 1v1 PVP or against AI and is far too overpriced at $15 USD off sale.
The game itself seems to never go on sale and with the current state of the game it is far too overpriced for the many parts that feel like Beta Placeholder content.




Conclusion:
I'd love nothing more than to say "yeah, go ahead and buy the game!" but I can't and it's not because I don't like the game but because whatever you purchase could very well end up mangled and twisted beyond recognition at the whims of a developer who only just recently (as in 1.5) gave the Campaign a mini-map, removed a feature many used, and more on top of being so utterly draconian in terms of moderation that it's on the same level as that time Ubisoft banned anything with the word "We" in it on the Assassins Creed forums. Sure, no one can stop you if you want to buy the game still but be warned there's a lot of problems here, you can be banned at the drop of a hat for saying something the developer takes offense to and you have no way of knowing what that may be.
Honestly the best hope and saving grace for this game at this point is mods, if mod support were to come then the developers could just leave and let the community take the lead, Lord knows that'd probably be accepted better than the multiplayer was.

Now, if I wasn't banned before this review I definitely would be now, if you want more helpful and somehow still relevant reviews then look at Most Helpful (All Time) a lot of what's in those are still problems today and TheLostSpartan's includes more things related to developer behavior.

Oh, and for those who still want to get the game at least wait for a sale when the game is greater than 20% off if possible, don't waste your money, especially if the game is even worse than when I post this review.

I really want to like this game. It has beautiful fleet actions of cruisers and battleships fighting it out, with many realism features. 100s of different historical hulls. What not to love?

Unfortunately, it seems less ready for launch than when it was in beta. Lots of unnecessary opaque features have been added that make the game opaque. Major bugs (or worse, bugs that are treated as "features") persist for years with no fixes.
*Starting a new campaign. The loading times have been an old meme at this point. Go make dinner. Eat your dinner. Chat with some friends. Maybe the game will have finished starting by the time you come back. Switching between various GUI tabs: loading. Need to design a new ship: big loading time. Turn times also get obscenely long over time.
*Bizzarre economy. Some countries grow at at 13% annually, while others grow much slower, based on fantasy factors the player has no control over. The result over the a game spanning decades: some countries can have an economy 100s of times larger that any opponent.
*Combat oddities. From ships retargetting to wrong targets, to weird ship movement, to odd armor penentration mechanics. They regularly get "fixed" and "refactored" but after all this time, are still a problem.
*Campaign mechanics. Again, from AIs bankrupting themselves within the first year, to general opaque mechanics from fleet selections for battles, lack of task forces. Odd autoresolve.
*The ship designs wheel heavily into fantasy after around 1915. The light ship designs disappear. The lack of any terrain (all battles are in an endless ocean), and the lack of any real world threats (coastal batteries, aircraft...) means building nothing but super battleships works great. You need a minimal cheapest destroyer cover for minesweeping that doesn't actually need to fire a single shot in battle.

Overall it's a game with so much potential, which makes it very disappointing.

Its a great game

but every time I get some time to play it and get ANY type of progress in my campaign the game just deletes my campaign progress. Extremely frustrating.