With release just over a week away (6th August) I figured it's maybe time we had a thread for Age of Wonders: Planetfall.
I'm guessing most folks on the forum will already have at least a passing familiarity with Age of Wonders, but if not:
Age of Wonders is a series of turn based 4x strategy war games with a strong focus on (also turn based) tactical combat. There's 4 games in the series (if you count Shadow Magic as a game in its own right), with the first being released 20 years ago. Same basic genre as games like Fallen Enchantress, Endless Legend, Heroes of Might & Magic, etc, and especially the first game almost certainly drawing heavy influence from the venerable Master of Magic. I don't think it's too controversial to say it's one of the better examples of the genre, especially for its combat. For those with little knowledge of the genre, the somewhat lazy comparison that most people will understand is it's sorta like Civilization with XCom combat.
Age of Wonders: Planetfall is the latest installment of the series, and the first one since the developers Triumph Studios were acquired by Paradox Interactive. Where the previous games were all set in the same medieval fantasy world, this time they've decided to go sci-fi. That said, at its core it's still the same basic gameplay, using the same engine and most of the mechanics from AoW3. At launch it'll be available on PC, PS4, and Xbox One, with controller support. They've said they'll "do their best to get a Mac version out" but have no news about Linux. There's plans for 3 expansions, the first one being later this year (and being Paradox and the age we live in, there's a season pass option).
Super cheesy trailer with 80s style music (https://www.youtube.com/watch?v=J6X27sPdTcs)
E3 trailer (https://www.youtube.com/watch?v=PeDoHNZthX4)
List of dev diaries covering most new features (https://forum.paradoxplaza.com/forum/index.php?threads/age-of-wonders-planetfall-dev-diaries-list.1109320/)
(there's also a ton of pre-release streams and videos floating around out there, and I included links to some 'spotlight' videos in the Races spoiler below)
I'm not sure if people like these kinds of threads to have a lot of info on them - I've noticed most of the more recent new game threads have pretty brief intro posts, but I'm not good with brevity and I'm also quite hyped and have watched an unhealthy number of pre-release videos for this game, so I'll try to share what I've learned and list the main features and changes from the previous games below. I'll just use Spoilers so it's not too wall-of-text cos I've probably typed out way more than I should have...
Once upon a time there was once a big advanced galactic empire called the Star Union. Something bad happened and the Star Union collapsed. Some factions within the empire survived, but whatever caused the collapse took down FTL travel and communications, and so the surviving groups were stranded on their respective worlds. As a result a cosmic dark age ensued for several centuries, with some of the factions having to evolve to survive. But now FTL travel is back online and these factions are now competing to loot and/or restore the ruined Star Union worlds.
From what I understand there's a Campaign that gives you an initial choice between 3 factions, then as you progress you'll have the opportunity to play some of the other factions. I gather there's some branching choices, some of which may result in a shorter campaign than others. Unlike previous games, the campaign maps aren't fixed hand-crafted affairs, instead they've used the random map generator but with certain terrain features and events for the campaign hard coded to always be present.
The other option is good old fashioned one-off random maps with up to 12 players. They're under the heading of Scenario this time around, but I don't *think* there's any of the hand crafted fixed scenario maps like there were in previous games (research suggested not many people played them). I might be wrong about that. There's the usual sliders to determine things like resource frequency, terrain types, prevalence and strength of hostile wildlife, etc, and there's some preset options available.
For multiplayer you can have up to 8 players (and optionally 4 AI players on top of that) with options for Hotseat, PBEM, and regular online play - though the latter two are kinda one system now, because they've added what they're calling an Adaptive Multiplayer system where online games are cloud based and can switch between simultaneous turns if all players are online and classic turns otherwise (so you can log on, take your turn, then log off until you get the notification that it's your turn again). This also applies to combat turns, allowing players to do manual combat between each other in PBEM games, which wasn't possible previously (previously for PBEM you could do manual vs the AI but only auto vs other players).
In an attempt to deal with the issue of manual combat in multiplayer (it really slows things down, but it's also a big part of the game and people justifiably don't trust the AI not to get their units etc killed in auto combat) they've added "Combat Cards". Basically each player gets a set number of cards that they can spend if they want to do a manual combat, thereby limiting how often manual combat can be done but without needing players to agree to only use manual under X circumstances. Cards regenerate after a certain number of turns with both the max number of cards and turns required to regenerate are configurable during game setup. It's an optional system - you can just use informal agreements as before if you prefer.
There's 6 playable races (perhaps more accurately labeled factions) available at launch. I've put links to the faction 'spotlight' videos in the names, giving a brief overview of each faction's units/weapons and then a summary of their backstories.
Vanguard (https://youtu.be/ZbOdqEtprN8) - militaristic space humans that support their basic troopers with robots, mechs, and other vehicles, all equipped with a mix of kinetic and laser weaponry. They're almost exclusively a ranged faction with very few melee options.
The Vanguard were part of the Star Union's expeditionary forces responsible for claiming new worlds for the empire. They used cryosleep and STL travel to reach new worlds outside the empire and on arrival would build the gates (or whatever) to link them into the hyperspace network. They pretty much slept through the collapse, waking at their latest destination to find the Star Union was gone. Where the other factions had to spend the centuries surviving on their own and have largely moved on from the Star Union, the Vanguard slept through it all so they're very much about restoring and re-establishing the old empire.
Amazons (https://youtu.be/LlDjvS0jFz0) - bio-engineer space women that shoot acid bows (it calls them energy bows, but they do bio damage) and ride dinosaurs that have lasers strapped to their heads. Most of the Amazons themselves are ranged, but their dinosaur and plant-based critters usually have melee options.
The Amazons were an all female expedition of bio-engineers that got stuck on an untamed world when the Star Union collapsed. They used their expertise to modify themselves and the local wildlife so that they could survive and prosper (I think cloning of some sort was involved). They've become a kinda druidy faction living in symbiosis with nature, just more inclined to tinker with the environment to suit their needs. And to strap lasers to it.
Dvar (https://youtu.be/rwY8-IVx1ik) - russian themed captalist space dwarves that use modified environmental suits and mining vehicles with strong defenses and explosive weapons (though a lot of their units have melee options too, including their aircraft(!)).
The Dvar have their origins in mining consortiums (consortia?), basically strip mining everything for profit. When the Star Union collapsed they were stranded on a barely habitable and particularly hostile world so they had to develop new techs to survive, including their DV-R environmental suits and extensive underground bunker facilities. They all have Russian accents and vaguely Russian aesthetics, but there's no particular story reason for that as far as I can tell - the devs just thought it was cool.
Kir'ko (https://youtu.be/oVWEqKpfrGM) - psionic space bugs. Their frontline units are melee based, backed up by psionic support units (and a psionic sniper), with big bug artillery and such further down their tech tree. They also have a number of ranged biological attacks with names like "Battle Vomit".
The Kir'ko were the first sentient alien species the Star Union encountered, a pre-industrial civilisation with a psychic hive mind. Unfortunately for them their planet contained sweet space nectar that one of the Star Union's megacorps really wanted and, feeling the Kir'ko were in the way, said megacorp promptly conquered them, genetically lobotomised their queens to break their hive mind, and turned them into a slave species. Now that the Star Union has collapsed the Kir'ko free and have done a bit of accelerated evolving in the meantime. They're philosophically split between taking revenge on the remnants of the Star Union or reconciling and moving on to focus on restoring their queens and hive mind.
The Syndicate (https://youtu.be/to22S8HGI7I) - ruthless mercantile space nobles with a penchant for espionage and slavery. They deploy 'indentured' troopers using arc (lightning) weaponry, backed up by psionic overseers for support (including a fat man on a floating space chair), with some resurrection and unit capturing capabilities. They also have sleek floaty vehicles with "Psi-Tec" psionic cannons.
The Syndicate are essentially mercantile noble houses, that were established during the early days of the Star Union, conducting ruthless and often shady business practices, and often fighting amongst themselves. Once the Star Union became a full fledged empire, the Houses were forced to submit or be destroyed, though they continued their less ethical practices in secret - they're big on diplomacy and espionage (and the odd assassination) as a means to get what they want. Once the Star Union collapsed, the Houses banded together to become the Syndicate, to ensure they couldn't be subjugated again and were free to conduct business however they pleased once again. (I've seen some people make comparisons with the houses from Battletech, though I'm not familiar enough with the lore to comment on how accurate that is)
The Assembly (https://youtu.be/kbfKriTJ4I4) - cyborg space zombies. Well, not really zombies per se, but their heavy use of bionic reconstruction allows them to resurrect fallen units and create temporary units from enemy corpses. They have a mix of kinetic and arc weapons with a focus on melee. Their "vehicles" consist of the pilot's head and maybe upper body integrated onto a vehicle chassis.
The Assembly have their origin in a Star Union research project to create a race of super soldiers. When the Star Union collapsed these super soldiers rebelled against their researcher and military handlers and a long and dirty war ensued. Biological and nuclear weapons were deployed, leaving the world a wasteland and both sides sick and ultimately infertile. As a result both sides resorted to increasingly extensive use of bionics and cloning, and started scavenging the battlefields for parts and organs from the dead. As this practice escalated a new type of human emerged, as much machine as man, and the Assembly were born. They view bionic and organic parts as interchangeable and the normal humanoid body configuration as optional. Their origin has shaped their driving philosophy that harmony is found through destruction and reconstruction.
Planetfall has basically the same cosmetic customisation options for your commander/leader as AoW3 had, with all the usual stuff for faces, hairstyles, accessories, clothing, etc.
In terms of gameplay/mechanical customisation, things are arguably a little more limited than AoW3. You still pick a race, obviously, and on top of that you pick one of 6 Secret Technologies which are basically analogous to Classes from AoW3 (more on them later). However, you no longer get the three slots to pick specialisations like Fire Mastery or Explorer. You do get to allocate some points to traits though, giving things like bonuses to certain types of research, different starting equipment loadouts, bonus starting resources, that sort of thing. One nice touch is that the negative traits that give you more points to spend also come with a positive bonus - e.g. the Cruel trait gives the general population an unhappiness penalty, but the commander gets a morale bonus whenever they score a kill in battle.
Planetfall has added a few new resources compared to previous games, and rejigged (and renamed) existing ones as follows:
Energy - essentially combined Gold and Mana from the previous games. It's used to pay for new units & upkeep (but not buildings this time) and for most operations, which are roughly equivalent to spells.
Food - used to determine city population growth. It can be shared between cities, so you can have a city focus on food to feed the rest of your empire.
Knowledge - Research.
Cosmite - a special rare resource that's used for the production and upkeep of high tier units (which is one prong in the attempt to reduce the reliance on T4 spam from earlier games) and also for Mods used on all tiers of units (more on Mods later).
Influence - diplomatic resource. It can be used to insult and compliment other players to affect their opinion of you. Possibly more prominently, it is used when interacting with the neutral NPC factions (more on those later) to peacefully clear their armies or to buy units and mods from them.
Unused production in cities now carries over to the next thing being produced. I think research does too.
Although the map still comprises hexes the way AoW3 was, those hexes are now grouped into Sectors. Sector size and shape varies - most seem to be roughly 5-7 hexes from one side to the other, but I've seen ones that were only 3 hexes wide but 9-10 hexes long. Some Sectors contain hazards that gives a debuff to cities there or has effects on combat that takes place in that sector. Operations (aka spells) often target a Sector, affecting everyone within it.
When you build a city it's always in the central hex of the Sector, and the whole Sector falls under the city's control (the city gets any resource nodes in that Sector, so long as enemies aren't sitting on them). As cities grow they can annex adjacent sectors, with a cap of 4 annexed per city. Once a sector has been annexed the owning city can specialise it towards Production, Energy, Research, or Food, with research providing specific buildings for each specialisation type. Terrain also gives bonuses to production of the specialised type, once you unlock it via research. New cities cannot be placed in a Sector adjacent to another city. Colonizers also have a Cosmite cost. A lot of this is at least in part intended to reduce the city spam that AoW3 sometimes suffered from.
Cities also now have population and job slots to assign in a similar way to games like Endless Legend. The number of job slots for each resource type depend on the types of specialised sectors the city has, and the buildings it has built. These also affect how many resources of the given type each unit of population produces when assigned to that job (so a city with a mountain sector specialised in production will have more production job slots and will get more production per pop assigned to them than a city in grassland specialising in food).
Cities now come with a basic built in garrison to defend them in combat. You can build military structures to upgrade them to increase the and number and tier of garrison units, along with adding defensive turrets. No more losing your cities to a lone raven scout.
Operations are basically the equivalent to spells in the previous games. They come in 3 basic categories: Doctrines, Strategic Operations, and Tactical Operations.
Doctrines are basically empire-wide buffs that do things like give production bonuses for each Forest sector you control, or a small amount of research for each enemy you kill. They usually cost energy to deploy, but are permanent once they're up and running (unless you manually cancel them). You have only have a limited number of Doctrines active at a time - to start with you only have 1 Doctrine slot, but you can unlock more through research - I think it caps at around 6-8 slots.
Strategic Operations are used on the strategic map (surprise!) and do things like provide a buff to a city, damage a stack of enemy units, or heal/buff a stack of your units. I think there might be some unit summons in there too. They also include Covert Operations which can be used to siphon resources from other players, fabricate casus belli, reveal enemy locations, etc. Covert Operations have an operation strength and each empire has an operation defense value (both modifiable by research and probably some other things) which determines their chance of both success and detection by the target. Some operations cost Energy to use, while others cost Influence.
Tactical Operations are like the spells used during combat in AoW3, doing much the same things - direct damage, buff/debuffs, summon units, etc. I think they all cost Energy to use.
One change from AoW3 (and possibly the earlier games, I forget what system they used) is Operation Points - the equivalent of Casting Points - are now separate for Strategic and Tactical Operations. So gone are the days where you cast a buff on your city, then got into a fight on the same turn and couldn't use a fireball in the combat because the buff used up all your casting points (or vice versa).
Another change is you can now have multiple Strategic Operations 'primed' at a time - in AoW3 if you spent e.g. 5 turns preparing a spell, you couldn't start another spell until you cast or aborted the current one. In Planetfall once you finish 'casting' an operation it is moved into another window as 'Primed' and is ready to use at any time, but that doesn't block you from starting another Operation. As far as I know there's no limit to how many you can have primed at a time.
In previous games in the series (certainly AoW3, I forget for the earlier ones), when your non-hero units gained experience and ranked up they often gained new abilities in addition to stat increases. E.g. Goblin Plague Doctors gained several types of debuff on their attacks. Also, hero units could equip a number of items in rpg-lite fashion, with slots for helmets, shields, weapons, boots, etc.
So in Planetfall that's changed a bit, at first glance for the worse - regular units mostly just gain basic stat boosts (accuracy and health) instead of new abilities when they rank up, and heroes now only have two equipment slots - main weapon and secondary weapon.
However, this is offset by the introduction of Modules, hereon referred to as mods. Basically each unit - both hero and regular - now has 3 mod slots. You can gain mods by researching them, find them as loot when clearing out resource/treasure sites, or by trade or quests with neutral NPC factions. Each mod will provide the unit with some sort of stat boost but often also give additional abilities such as adding debuffs or status effects to the unit's attacks, giving the unit a short range flight (jetpacks!) or teleport, healing the unit (or giving it the ability to heal others), adaptive defenses that buff the unit's armour each time it's hit, and so on - there's a lot of stuff in there. You can swap mods in and out on the strategic map (though it has a cost associated and applies a debuff to your unit for a turn while it switches) but you can also set up templates for each unit so you can build them pre-modded in your cities.
Mods are another prong in the attempt to limit T4 spam - the idea being that lower tier units stay relevant into the late game through mods.
One other thing to note is that you can equip mounts and vehicles in place of your heroes' primary weapon. This will give the hero the attacks and stats of that particular vehicle or mount and if they die while mounted or in a vehicle the vehicle/mount is lost but the hero jumps out on foot with (I think) 15% health (albeit without a primary weapon until you equip another after combat). Heroes can equip any of the vehicles & mounts you can research as regular units. I think they retain any of their special abilities while in a vehicle.
Roughly equivalent to Classes from AoW3, in addition to picking a race you also pick a Secret Technology - as with AoW3 the number of race/tech (aka class) combinations mean there's still a lot of options despite the smaller number of races and specialisations from previous games. Each Secret Technology provides a branch of research containing 3-4 units (some of which have slightly different traits depending on your race), along with Operations and Mods. Getting to the end of a Secret Technology research tree gives the option for a 'doomsday' victory - basically you do a thing with your tech that gives you bonuses, everyone else penalties, and they have 10 turns to shut it down or you win the game.
There are 6 techs to choose from - there's not been the same level of official info released on these, so here's what I've pieced together:
Xenoplague - an alien virus which has been engineered for both beneficial and offensive purposes. It has three units which all have to be spawned by infecting and then killing enemy units - the number and tier of the units infected determines the chance of getting a new Xenoplague unit at the end of combat. It also has unit mods that infect your units with beneficial strains of the virus for health boosts and protection from certain status effects (complete with a visible parasite on their backs), or to equip them with plague attacks. The doomsday option is basically to infect the whole planet with the Xenoplague, building spires to pump it into the atmosphere.
Promethean - basically kill it with fire technology, that came into being to fight the Xenoplague. It provides little melee based plasma robots, power armoured plasma infantry, a kinetic based tank that can shield nearby units, and a plasma/fire based mech. Its operations and mods tend to be offensive in nature, though it also has options for removing or resisting debuffs and reducing or removing the penalties for hostile terrain. The doomsday option is essentially the Exterminatus option - pump the Promethean "PyrX" gas into the atmosphere, then ignite it to burn everyone and everything while you sit in your specially shielded bunkers, ready to claim the world when it's done.
Voidtech - break the laws of physics with various applications revolving around manipulating time and space. It provides a melee based infantry unit that can spawn a duplicate of itself (I think lore-wise you pull it from a parallel universe), and has a "Rift Generator" tank that does an AoE blast attack which both damages and randomly teleports anyone caught in the blast. I don't know much about their mods and operations, though I know one makes the user harder to hit and lets them walk through terrain. The doomsday option I'm also a little hazy on, but I gather it involves drawing energy from the Void (and I think draining everyone else's energy).
Synthesis - AIs and hacking and suchlike. Provides a lot of options for disabling and destroying robotic and mechanical units, whilst allowing you to install "daemons" on your units to boost their capabilities whilst also integrating them into your network - a lot of the mods and operations give buffs to units with the "integrated" status. I'm not sure about their later units, but the starting one are "Hackers" equipped with a lightning SMG and with abilities to mess with enemy robots and vehicles. The doomsday option is to upload everyone's consciousness into the network.
Psynumbra - sinister evil psionics, originally used by the Star Union's secret(?) police until their leaders started abusing it for their own dark pleasures. Tends to revolve around creating and exploiting suffering and summoning spectral creatures from the Abyss. e.g. it gives access to Devour Hope, which applies a hefty morale debuff to the victim, and if they die while afflicted it spawns an "Echo of Despair" unit in its place under control of the Psynumbra player. I don't know what is doomsday option is, but I'm sure it's unpleasant.
Celestian - in some ways the counterpart to Psynumbra, this is the 'good' psionics option. Lots of healing and support stuff, with a focus on peace and enlightenment (I think they have an operation that if successful prevents the target from declaring war on them). Comes with a melee unit that has literal fists of fire, and a psionic support unit. The more sinister side of Celestian technology involves influencing the minds of others - I think they may have some mind control powers, and from what I understand the doomsday option basically has you flooding the world with your psychic message causing everyone's population to leave their cities and join you.
Unlike previous games in the series which had (semi) randomised research, for Planetfall they've gone for a more linear research tree. There's two main categories of research: Military and Social, which can be researched simultaneously.
The Social tree primarily consists of buildings for your colonies to improve resource collection, happiness, etc, and Doctrines which are basically empire-wide buffs. It also has a branch devoted to increasing your operations capabilities, along with covert operations to do things like siphon energy from another player. The Social tree is mostly identical for each player, though a handful of the techs (all doctrines, I think) are determined by your choice of Secret Technology.
The Military tree is split into 4 paths (which branch a bit):
Racial path - this contains all your racial units, mods, and operations. Unique to each race, though there's certain consistencies (everyone gets a flying unit, everyone gets a boat, etc).
2 Weapon paths - each race has access to weapon groups and get a research path for each. These are fixed for each race, but with the exception of the Explosives path (which only the Dvar get) they are shared between multiple races e.g. both Amazon and Kir'ko get the Biological research path.
Secret Technology path - contains the units, mods, and operations for your secret tech (aside from the handful that get slotted into the Society tree).
If you manage to acquire a colony containing another race (e.g. because you conquered them), you gain access to that Racial research path as well. So in theory you could research Vanguard jetpack mods and equip them on Kir'ko melee units.
From what the devs have said (which is supported by most of the streams I've watched) you generally won't have time to research everything in one game, so there's decisions to be made as to what to focus on for a given playthrough (which in theory increases replayability).
Each map will be home to a number of initially neutral NPC factions (I think the default is 2, but I believe that's configurable in game setup). These are roughly equivalent to the Dwellings from AoW3.
When you first meet an NPC faction you typically get the choice of saying hello nicely, or declaring war. Certain courses of action during the game can also result in them declaring war on you. Unlike the Dwellings in AoW3, if an NPC faction is at war with you they'll not just defend the domain around their city (in this case, Sector), they'll actively build and send armies across the map to attack you.
If you stay friends with them though, they'll give you quests to kill units, build things for them, or do research for them. These quests will always give an Influence reward and will increase your Favour with the faction, along with some resources or maybe a free unit or piece of equipment. As you raise your favour with a faction you'll increase your relationship status with them, which opens up the ability to trade with them, spending Influence to purchase units, mods, and I think operations.
At the highest level of favour you can integrated their cities into your empire (though I think you need to have an annexed sector adjacent to their city(s)). I'm not 100% sure what that provides you, or whether it cuts off other players from trading with them etc.
Also unlike AoW3, the NPC faction's units can be found guarding resource nodes well away from their cities. Attacking them is an act of war, but you can spend influence to ask them to leave peacefully (which as far as I can tell they always accept, although the price may vary depending on how much they like you etc).
Factions will occasionally make demands for resources - typically you have a choice of give them the resources or do a quest instead. Sometimes you can just ignore them but sometimes that will prompt them to declare war (you get a warning if that's the case). I'm not 100% sure, but I think if you ignore the demand you lose favour, and if you don't have the favour to lose that's when it escalates to war.
There are 5 NPC factions at launch:
Growth - sentient plants (plus bees) that want to live in symbiosis with everyone. Which unfortunately includes mind control pheromones that lure colonists into their jungles, never to be seen again.
Paragon - elite Star Union citizens along with their guards, kept alive all this time by their high tech cybernetics, though they've gone a little mad in the interim. Their guards didn't get the really good stuff, so they're basically cybernetically animated corpses at this point. Some obvious similarities with The Assembly - it was the Paragon Corporation that ran the research project which birthed them.
Spacers - the lower classes of the Star Union citizenry, they were kept docile through drugs and freely available VR entertainment. After the collapse, both the drugs and VR were largely cut off and the citizens had a rude awakening to post-apocalyptic reality - those that survived have gone all Mad Max, mixed with a parody of gamer slang and culture.
Psi-fish - (not their real name) extra dimensional creatures that have trouble understanding life on this plane of existence. They tend to devour people's minds and implant their eggs in people. Fun times.
Autonoms - originally Star Union emergency services robots, after the collapse they were cut off from the 'CORE' mainframe. Over time they linked up and developed into a new sentient collective.
The core of the diplomacy in Planetfall is much the same as previous games - and indeed most 4X games - but they say they've tried to improve things a bit in terms of foreshadowing their behaviour so they don't seem so random and making them seem more like living entities in their behaviour. No idea whether they've succeeded in that, but there are a few changes and additions worth noting:
As mentioned earlier, you can spend influence to insult or compliment other players, affecting their opinion of you. You can make them general or sometimes based on a specific thing they've done, but that just affects the flavour text. I'm fairly sure I've seen denouncements similar to the later Civ games - messages like "Bob has denounced Susan for use of covert operations". I'm not sure exactly what those do, whether it's just flavour or if people that like you will dislike the people you denounce.
Casus Belli is now a thing. Insults, Covert Operations (if detected), trespassing, settling sectors that are 'claimed' (i.e. adjacent to a city or annexed sector), and probably some other things will all give casus belli points against the transgressor. Going to war when you have casus belli points against the target will result in a boost to your popular support - you'll get reduced unit upkeep, increased morale, etc. More casus belli means higher support bonuses. Going to war when you don't have casus belli will reduce your reputation and I think maybe upset your people (unsure if that means penalties, or just a lack of bonuses).
Casus belli points can be traded with the target - I saw the AI often offer energy or cosmite to the player in exchange for the casus belli they had against them. Essentially "here's a bribe if you forget that bad stuff we did to you".
Vassalage is now a thing too. If you become a vassal you can no longer start wars, and if your overlord starts a war you're automatically included in it. You can no longer denounce or warn your overlord (and possibly other players too?). You can't make or break treaties. Only the overlord can end the vassalage, and they do so by declaring war on the vassal. The only way out of being a vassal is if the overlord is defeated. So it's not a great state to be in, but might be better than outright losing.
Alignment is gone, replaced by Reputation, which you gain and lose in much the same way - displacing populations with migration, razing colonies, etc reduces your reputation, while completing quests, offering gifts, forming pacts increases it. Higher reputation means other high reputation players like you more and NPC factions charge less influence when you trade with them. Bad reputation causes people to dislike you and apparently results in casus belli against you (not sure how that's handled, given you can buy back casus belli against you).
For the most part combat in Planetfall is very similar to AoW3, though being sci-fi there's arguably more ranged combat going on this time around.
Although it works in almost exactly the same way as before, action points are now explicitly a thing. Each unit has 3 action points; repeating attacks will fire once per action point, and moving will reduce how many action points are available for attacks and other abilities (with a colour-coded overlay to show how many action points you'll have left if you move to a given hex). Some attacks and abilities only ever fire once no matter how many action points you have (but still end the turn even if you had spare points). Some attacks and abilities require a full 3 action points (typically only allowing you to move 1 hex if you want to use them).
One small change there is that where in AoW3 you always had effectively 1 action point however far you moved, in Planetfall you can move a bit further 'into the red' leaving the unit with no action points (I'm not sure if that's extra movement compared with AoW3 movement ranges, or just that you can't move as far while retaining action points compared with AoW3). This has two main effects: 1) you'd not be able to use any attacks that turn, and 2) you can't go into defensive guard mode at the end of your move.
Missing is a thing again - much like the earlier AoW games, units now have a chance to hit which is affected by things like range, terrain obstacles, unit abilities, whether the unit is in guard mode, etc. But to make the RNG a bit less frustrating (and less like XCom), there's Grazes. All attacks have a 25% chance to graze before the hit chance goes on to misses. Grazes do half damage and I think don't apply any status effects or debuffs that the attack might otherwise apply. So e.g. a 20% chance to hit attack effectively does a d100 with results 1-20 hit, 21-45 graze, 45+ miss. This means if you have at least a 75% chance to hit you'll never completely miss.
Overwatch is now an ability certain units have. It works in much the way you'd expect it to. A unit going into overwatch specifies which direction they're covering - the system shows you a pink overlay of the hexes they'll cover in the current direction you have selected. If anything moves or uses an ability in that area, the overwatch unit will shoot at it. A unit in overwatch will only trigger once(I think there might be one or two units that can exceed that, but not 100% sure), though if they have a repeating attack their triggering attack will shoot once for each action point they had when they entered overwatch. Melee units automatically go into melee overwatch at the end of their turn and melee overwatch triggers whenever any unit adjacent to them moves, uses an ability, uses a ranged attack, or misses/grazes with a melee attack against them.
Stagger - there's a few new status effects and debuffs, but one that probably bears mentioning specifically is Stagger as it changes things up a bit. A lot of kinetic and explosive attacks, along with I think all melee attacks, have a chance to apply Stagger. Stagger does two things: 1) it knocks units out of both Overwatch and Guard mode, and 2) it removes one of the target's action points for the next turn. A unit can only lose 1 action point per incoming source (so you can't strip all 3 action points away with a single repeating attack), but multiple sources of Stagger can knock off 1 action point each, leaving the victim completely unable to act in its next turn. Understandably it's possible to get Stagger resistance from abilities and mods.
Experience is now averaged out for the whole stack at the end of combat - no more gaming the system by ensuring particular units get the killing blow, or cycling through as many abilities as possible before finishing off that last enemy (which some people will miss, but on the plus side it becomes easier to level certain types of unit).
Still no ability to decide your units deployment formation in advance, but I gather battlefields are a little larger so you'll generally get a turn or two to move things around before combat starts proper.
Most sources of cover can be destroyed (though some require a specific "Demolisher" trait/ability).
Tactical Operations aren't available until turn 2 of combat.
I think that's just about everything. Personally I'm really looking forward to the game; Age of Wonders is probably my favourite strategy series and I can't wait to set up my Celestian Assembly so I can bring peace, enlightenment, and horrific dismemberment and bionic reconstruction to all.
(https://i.imgur.com/eDJQCNW.png)