Planetfall is a scifi spinoff of otherwise fantasy 4X series, and while it has some neat depth to it, it doesn't get introduced properly so initially it may feel much closer to Civ or other major hexagonal army guiding and city plopping - it takes time to figure out the nuances that make it feel more intriguing. If you look at reviews you will see folks complaining they played a little and it felt samey to other established 4Xes. They're wrong but it's on game's side it doesn't highlight stuff well enough.
Let's start with setting and factions. There' used to be a Foundation-style galactic Empire of humans but then it fractured, so now a bunch of factions are trying to establish themselves on the individual planets to form their own states, salvaging in the untamed lands full of abandoned labs and factories. Since this is a fantasy game's spinoff some of factions actually maintain fantasy influences, like Dvar are Volus-style pressure suit wearing dwarf-likes, with a focus on demolitions, corporate style disregard for environment, and dwarfish honor intertwining with industrial conglomerate pragmatisms. Amazons while being an all-female nation also give off major elf vibes with their focus on nature down to getting incentives to turn your lands into lush forests. Then, the Assembly are a mix of Borg or Strogg style cybernticised humanoids, but they are so blase about reusing own dead and their cybernetic ribs and hipbones are so exposed you can really trace their lineage to undead. The only proper aliens are former human slave insects who got ajacency combat bonuses in combat and focus on rapid growth, which is a downside when you think of space opera, it's very human-centric with varities of posthumans instead of proper alien race scuffles. There's also a Secret Technology selection which is another choice independent from race, it gives you three new units, abilities and it usually offers some means of diversifying your loadout, either letting you synergise with the rest of your roster, or introduce alternative when you're getting hard countered, even though I don't think it compares to full on synergies efficiency-wise. Also the section of these techs is pretty modest. They all fit into a pretty defined theme like "psychic powers" or "reality warping physics" or just "hacking", and also offer some distinct superweapon to end game with.
Let's get to the main map matters. As many scifi 4Xes it doesn't feel as intuitive as it could be, trying to offer a variety of alien terrains, even if many are recognizeable like "lava land" or "normal terrestrial forests" you will still depend on tooltips a lot to figure out what regions are best to claim and what are the nuances. Also, unit travel is kinda slow in this one, up until mid to late game where you get some fast travel options. BUT the way how districts and expansions of cities are handled is pretty nice, more or less streamlined and offering some interesting options most of time, even if it takes time to get a grasp on things and they may feel bit simplified initially. There is an espionage mechanic that instead of handling everyone trough individual spies like many games just has you call in abilities targeting players or their cities, and as you progress you increase your power. Wish it was integrated kinda better with more reliable means than science tree progression to buff these but as is it's not fiddly, pretty intuitive even.
Now, the tactical battles! These take on their own maps depicting location it takes place in, and they're all surprisingly detailed! All the units are pretty distinct in many ways here, and so are the heroes who can be customized down to giving them vehicles up to second best the faction can offer! Also, both units and heroes get means to grand them new abilities or give passive bonuses which can matter quite some when trying to turn the tide, though it unfortunately does add some extra micromanagement to it all. Anyways, the combat! Another important bit that actually ties into similar researches as espionage but also into hero abilities and other details is the tactical abilities you can call in. It can be a game changer to give your units special boons, deploy reinforcements or pull off other tricks, but it costs both your main currency AND there's a limited amount of these calls in to be released in a battle so you really have to be as selective as possible with these. It's like player-cast spells refluffed for a scifi setting though, effectively.
One thing I previously mentioned as weak is game actually easing into it's concepts and nuances in way that makes you realize it's distinctiveness better, but also this extends to say the in-game encyclopedia while documenting every effect, unit, ability and other feature also lacking cross-linking that would let you, say, look up the mechanic the ability mentions, instead you gotta input a whole new query. The tutorial isn't good at making you figure out everything beyond very basics, either.
This one's a pretty cool 4X since it dares to drop a whole smorgasbord of scifi tropes like post-apocalyptic scavengers, psychics, sentient robots, mutants, anomalies and etc and has you eke out an empire in this madhouse, offering a variety of stuff, just may take some time to get a grip on things. Also I recommend grabbing the full package since some of the additions quite add up to variety.
