It is a sequel that takes place after a 30 year timeskip from the first game. The first game appeared to have at least four different ending states of the city of New London: secular state or "religious" community, and then whether or not you (the captain) become a dictator/cult leader. Early on in this game, you get a prompt telling you to select whether New London when secular state or "faith", but no option for whether the captain went dictator/cult leader. When I arrived at the city, it did not feel like how I envisioned my city from the first game would become thirty years later. Yeah there is a "faithkeeper" faction, but they don't seem to be even vaguely sincere or followers of Christ like what was sometimes hinted at in the first game. Here they have gone fullblown vague spirituality and worshipping "holy generators" and other schlock. Not a single mention of Christ.
Another thing is that the community feel my city had in the first game is gone. This is mostly a change in/absence of presentation. In the first game you would get prompts that you would click on that would then blow up and show you an illustration/scene/diorama of what was happening on the ground, and there were a few characters you would recognize over and over. But in this game, you do not get anywhere near as many prompts about what is happening on the ground, and when you click on them you either get a small window with an even smaller image in it, or you get a cutout of a face and not a whole scene. Aside from maybe the faction leaders, it does not feel like there are any characters to follow from these prompts, besides the drunk.
Overall it makes the story feel more like it is just tooltip flavor that is secondary to a city builder, rather than one of the main parts of the experience like in the first game.
The main gimmick of FP2 is trying to balance the different factions within your city, who are the population and also have proportionate representation in the council/parliament chamber. The groups may have overlapping or differing interests which determines how the senators may or may not vote. You can try to skew the voting by making backroom deals with the different factions, having most of their senators vote for or against whichever law is currently being voted on in exchange for you doing something for them, usually by building or researching something, but sometimes you get the option to just pay them a little money. Or offering to put their agenda on the docket for the next vote, though for that vote you don't actually have to make their bill pass.
For the "vote" button, you (the Steward) do not actually get a vote (unless you start going down the dictator tech tree). Pressing vote just proceeds to the actual voting, so unless you are sure you will likely win (or don't care about the bill) you instead push negotiate to go the next screen.
Here you can see which factions are the most likely to adjust their votes and how much voting power they have. You click on a faction and then that leads to the next screen where you get three deal options.
I was strapped for cash for nearly the entire game, right up until the last couple hours. The alcohol revenue was pretty significant and I am not sure if I would have been able to get those rush orders done at the end to broker the peace deal and win with zero casualties without it.
Then when you're done you click "vote" and then it is up to who you made deals with, the size of a faction (and thus how many senators they have) and some RNG that determines the outcome. I liked how representatives have lamps at their tables that they light to signal their approval of a bill.
Near the very end of my playthrough, the Faithkeepers finally accused me of doing backroom deals against them (which I had been doing for almost the entire game), and then demanded that I make one of their laws pass within 40 weeks.
The factions also have a few stats/meters attached to them. Their trust in you the Steward (is a different stat from the city's overall trust in the Steward), their fervor, and how large or small of the city's total population that faction encompasses. Doing various different things throughout the game will raise or lower these stats, and since the factions can have overlapping and/or opposing interests, that means it can become difficult to please everybody. But as long as no one's trust in you reaches the bottom, then they won't start rioting or try to overthrow you. You also don't want any faction's fervor to max out, because then they start doing stuff like invading other faction's buildings or trying to push for "radical" laws. Lastly, the size of a faction is a double-edged sword, since factions that like you will do stuff for you and grow bigger, but if you are nearly maxxing out their tech/law trees then they are going to start pushing for the "radical" laws (similar to "crossing the line" in FP2), and their large voting bloc makes them much more difficult (perhaps impossible) to fight against, and then there might be another faction with overlapping interests that might be able to push their vote over the 51% mark and lock you into a certain ending.
I went into this sequel thinking I would support the Faithkeepers, since I picked faith over secular state in the first game and got a dialogue prompt to sorta import my choice. The Faithkeepers here turned out to be loonies, but we got introduced to a new faction called the "Frostlanders", and their faction leaders in the toolbar icon and in the council bio looked like wise elders and experienced wilderness survivalists. Their shtick of trying to research moss filters or teaching people how to incorporate mushrooms or berries into their food instead of chemical additives appealed to me, so I started buddying up with them and going down their tech/law tree.
Eventually, a sect within the Frostlanders emerged called the Evolvers. I am not sure if this happened because I kept leaning Frostlander or if this was scripted to happen no matter what, but the Evolvers were mostly more of the same stuff I wanted (doing some prosthetic limbs, more wilderness survival stuff, etc). So I researched their tech and approved laws they liked, and then soon enough they were growing in numbers, loved me as Stewart, and then began doing research free of charge like prosthetics or pacemakers, and then they got so fired up they started doing rallies across the city and asked me whether they should rally the citizens to pay more taxes or go around training people. It's a whole faction of Hulk Hogans! I loved these guys.
They even started developing tech on their own like better heating tech or amazing prosthetic limbs and submitting it to me for approval and mass production! They went around trying to make us a city of gigachads. To make us the best men we can be.
Apparently this masculinity begins to intimidate some people.
The evolver leader is so awesome, he keeps his people in line while the Faithkeepers are losing their minds.
Eventually, I had reached near the end of the Evolver's tech/law tree. The Evolvers proposed to pass a law to make us even better. This is where we start getting into the strange morality of the devs/writers again as
@DemoGraph mentioned earlier. Apparently, becoming the best man we can be is somehow crossing the line into "evil", and will lock you out of the "good" ending. What? I checked, and the other radical/"evil" laws I have seen include sterlization of prisoners, commie reeducation camps/gulags, Muslim janissary **** of ripping kids away from their parents and having other people indoctrinate them and giving them new names. But the writers are equating becoming a nation of gigachads with that? It's weirder too when there are pretty definitively evil laws that are inexplicably not labelled as "radical", such as Brave New World styled merry-go-round casual sex for all, and so on. And objectively good things like putting people into insane asylums is inexplicably considered radical aka evil and will prevent you from getting the good ending. What is this nonsense? Why do the writers think this way?
Anyway, since the Evolvers had grown to be about 33% of the total population, and they overlapped with the Frostlanders who were around 25-30%ish IIRC, those two blocs pretty much guaranteed that the vote would pass no matter how many negotiations I did trying to get people to vote against it, which would lock me out of the "good" ending. So I had to reload an earlier save and somehow start getting people to abandon my beloved Evolver faction and go to the other factions. Hence why loving a faction is a double-edged sword in FP2.
Anyway, my experience with the first game taught me to be very conservative, and to amass a huge safety stockpile of all resources (fuel for heating, housing for unexpected large influxes of people, lots of mats to quickly build new stuff, etc). So I kept sending my scouts out to explore the world map and they discovered lots of encampments, but I kept delaying bringing any people back. The issue was that housing was the one resource I could not get a comfortable lead on. In FP2, your city's native population is reproducing, so every so often there is a census and suddenly your population count has increased and you now have more people than houses to put them in. And the birthrate scales with your total population size, so the later on into the game you get the more and more people are born and have to be housed. Starting with the midgame, when I had a humongous lead on every other resource besides housing (food and oil that would last for decades), I made a concerted effort to try to build as many housing districts as possible so that I could finally start bringing the people out in the world map into my city, but I never got a comfortable enough lead to do it.
Eventually I colonized Winterhome, which I was overprepared to do, which then triggered a civil war back in New London. The faithkeepers crying about the Evolvers again and now they are out on the streets torching buildings and mobbing evolvers. Hilariously, the UI kept describing the situation as two groups fighting each other as if there are two groups you need to placate, but the Evolvers had zero fervor, meaning they weren't going out fighting anyone. It was all just the Faithkeepers going out attacking people.
Fortunately I was able to call the guards and throw them in prison, called up the Faithkeepers to find out their demands (I selected the options to research and build 6x of their crappy stuff factories and mines), and used my 4x research labs and my humongous resource reserves to get it done within a few weeks. I bribe the city folk into voting yes to saving their own city. (The New Londoners had become a minority within their own city, shrinking down to 23%. I had successfully converted the city into majority Frostlanders/Evolvers aka gigachads). We pass the peace accords, war is over with zero casualties or districts burned, and then that's it. That's the end of the game. Felt a little anticlimactic compared to the storm at the end of the first game.
Weird thing to try to guilt the player over turning away freeloaders in a post-apocalyptical survival sim.