I have been playing 4x strategy games for 23 years. I remember installing Civ 1 and gluing myself to the screen. My parents would threaten me with "No civ!" from time to time and boy that worked. I went on to play and enjoy every other version of the game, extensively, despite the changes that frustrated many.
Alpha Centauri was my jam. I probably had thousands of hours played, and I STILL have it installed and still play it; in my opinion it was the best in terms of immersion and strategy. I would LOVE to see steam carry it, it would sell very well and I would have people to play with multiplayer again.
ANY WAY, this game is the modern sequel to Alpha Centauri in spirit; If you haven't played Alpha Centauri, I apologize for the reference, you should go look it up and get your hands on it. It's brutal, immersive, and has endless playability, as is Pandora. The game is not perfect, and is still being devved and updated (I trolled their forums a bit and their devs actively respond to questions and comments), but is still beautiful and brutal at the same time.
Strategy wise, it is incredibly complicated however you can start out simply till you learn the ropes. Customizable units means that you can get intel on what your oponents are using (with your nifty satellite recon operations, which are very useful), OR you can out tech everyone and have mega upgraded units that are good against everything and nearly immortal. The latter is much more difficult and expensive. It is easy to learn but hard to master, I still find myself changing my strategy mid game; discovering a new technology could change the tide of battle very easily. Getting intel that an enemy fleet is about to hit your mainland when your army is off fighting on another continent? No problem, you can research drop pods to recall your troops back to the mainland, and watch them drop from orbit to obliterate your foes on the beach.
Mid and late game can be VERY VERY HARD if you don't know what you are doing, which is something they are working to patch. The eclipse isn't so bad, but the messari invasion can be very frustrating. Here's the thing though, if you stick through it, it will make you a better 4x player. Every game you lose you will learn something from... And YES, you will lose at first. I recommend starting on very easy and low aliens until you get the hang of it. Learn to skip techs that you know you do not need based on what your armies and infrastructure need. It will take a few playthroughs to get the hang of this... The random tech tree was odd at first, but I ended up liking it very much, it gives a very unique feel to every single game in terms of the strategic decisions you make.
It is a very immersive environment, beautifully however simply rendered. Watching leviathans in the water waver, surfacing a bit and then going back down to a silhouette. The combat could be done a bit better in terms of animation, but it is not too lacking, and I can't be quite that picky as simplicity is beauty. This is a game I play on a 7 year old desktop, and it still looks good and lags just a tiny bit late game. I love watching the world darken for the eclipse, and then re emerge to light afterwards. Clouds of ash and infestation encircle the world and darken it a bit again for the messari invasion. Late game is my favorite... Dropping nukes on people, turtling then dropping massive surprise armies on people's continents, and if you are lucky enough to survive late enough and tech up well, you can SUMMON TACTICAL BLACK HOLES!!! Alternatively, pissing enemies off whom have out teched you will result in a very depressing loss via having your cities obliterated by enemy black holes. Such is life in Pandora.
It could use more music tracks and animations for leaders, and I'm sure they could afford like... Sir Patrick Stewart to do some voice overs for them.
Espionage is OP and defending against it can be frustrating. Surround your cities, and keep an eye on the events log to see when they are spotted. Espionage is getting re worked in a patch at some point, so I have heard.
Unit stack can be crippling. Being a veteran to 4x will help with this, but you can go half a game successfully and then have a very tragic loss via an insurmountable wall of enemies. In Pandora's defense, this is counterable by having good intel and making sure your armies are diverse enough. Also, orbital bombardment via satellite and artillery units are good counters to this.
The AI is dumb in the water. They will leave unit stacks in the water while moving troops, and this leaves them very vulnerable. Much similar to Civ 5.
Diplomacy could be more diverse and useful.
The AI likes to plant cities in your territory if you don't fill gaps between your cities. This is VERY frustrating, but again hopefully getting patched.
The Messari invasion will kill you until you learn to prepare for it. This, again, is getting patched (they need to either make it later or have a difficulty setting specifically for it). Preparing for it mean covering your territory, and having a diverse (and not small) army and enough production to continually resupply yourself with troops.
This is way too long of a review I need to stop typing. 9/10!