Age of Wonders: Planetfall

Originally, I wasn't going to recommend this game because it didn't meet my expectations as a Paradox game, or as a complex 4X game. If you're expecting a typical Paradox deep grand strategy game, this definitely isn't for you. DO NOT PLAY THE ENTIRE GAME USING AUTO COMBAT, OR YOU WILL HATE THIS GAME. That was my initial mistake.
Once I was able to manage my expectations, Age of Wonders: Planetfall is a very good game. So if it's not a grand strategy game, what kind of game is it? There are strategy elements, but most of the choices are no-brainers on that level. Just blob and grow as fast as you can, while ensuring you have a strong enough army to explore the map and defend your territory.
However, where the game really shines is in its tactical combat. Each faction uses its own units; each faction has its own heroes; each leader has a different secret technology (which customizes 1/4th of their military tech tree); each unit has its own abilities. If that's not enough customization for you, you can also research mods to kit out your soldiers. Even better, you can find special weapons and equipment specifically designed for heroes by exploring the world map. If you don't have hero weapons/equipment, you can outfit them with normal equipment available to your regular troops that you've researched in the military tech tree. Unfortunately, there doesn't seem to be nearly as much variety with the navies as there is with land units--although to be fair, if you consider infantry, vehicles, tanks and air force to be separate unit types then naval units have a similar level of diversity.
Units can also gain combat experience and improve their skills. Regular units improve base stats, while heroes can be customized when they level up.
There are dozens upon dozens of different combat maps. Each map presents different tactical challenges. Environmental objects can be used as cover, but they can also be destroyed. So if your enemy tries to hunker down behind a building, send a grenadier to blow up the building with a rocket! But be careful, because your opponent can do the same thing to you.
If you treat this game as a tactical combat game, more along the lines of X-Com than say, Civilization, Age of Wonders: Planetfall is a wonderful title that will provide you with a great many hours of entertainment.

Planetfall is tied (and likely exceeds) III as my favorite Age of Wonders game. Planetfall could easily be a desert island game for me.
I am quite saddened that Planetfall never gained traction or a sizable following...making a follow-up seem less likely or financially viable.
Age of Wonders 4 with its excessive focus on customization and lack of meaningful race/faction identities hasn't grabbed me as much. Each game of 4 feels very flat and similar. I'll keep giving 4 a try though.

By far the best 4X grand strategy game out there. If it's on sale, get it.
It does things better than Age of Wonders 3 (Heroes, unit customization, music, story impact, voice actors, damage types make more sense, looking better etc.) and even just crushes AOW4 in most aspects.
I recommend playing through the whole thing and then 100% the galaxy empire stuff, which is an meta progressing game mode where you level each race and technology separately to gain cross game currency and "upgrades". After that check out the interesting mods for this game which can completely change the way you have to manage your units.
It does have some flaws of course. Most important ones are the bad naval combat, stupid AI, unbalanced units, expensive DLCs (especially horrendous campaigns, I don't recommend playing these) and too few combat maps considering how many hours you can burn with this game and I did not play a single match online.
Even though I normally do not like sci-fi settings, this one is just interesting enough that I don't care.
Highly recommend, better than AOW4

Initially I could not afford the new AofW4 so I bought Planetfall instead. LOVE THIS GAME!
A unique and successful mix of turn based strategy, with civilization-like game and RPG - all my favorite genres together!
From the art, lore through variety of playstyles and replayability it is a well made game. I especially enjoy playing its biggest maps with the most AI players. Different factions of this game have different strengths and weaknesses, so a big game keeps you awake and challenged. Exploration is fun, expansion and conquest are rewarding. Love that taking over other faction's city gives you access to their tech tree, increasing your options for units building. This in return expands your options and styles in fighting battles.
The campaign in AoW Planetfall is just fantastic! You have a chance to play every faction and they way they are introduced makes you fall in love with all of them. And the campaign has multiple ways and outcomes to finalize it.
My first exposure to the Age of Wonders franchise and its overwhelmingly positive!

Good game, takes time to get used to but worth the investment. I distinctly remember wondering whether or not to keep at 2 hours, as I know the amount of knowledge I would need to learn to play (I am getting lazy in my age) but was worth it. Nice diversity between races, heroes could do with feeling a little more unique.
Simply; Civilization in space, simplified, but having the combat expanded greatly.

Need PlanetFall 2!!!!

This is a good game. I bought it (along with all the DLCs) when it first came. At the time, it just never clicked.
After putting it down for several years, I picked it up again while on vacation. It's now a fun, engrossing game. I would say - it's like Xcom merged with Civilization. Definitely good for 40+ hours. There is so much depth. I have only scratched the surface on strategy and tactic. I am not sure how much of the improvement is due to the developers just working on the game vs the DLC. Bottom line, if you like XCom and Civilization, this game works for you.