I played the Prison Architect freebie a bit over the last couple of weeks, and realized once more how much I like scratching that "builder" itch. Unfortunately I find the Prison Architect theme ... distasteful to such a degree that I no longer want to spend more time in that game (and that's a shame, as the game does a lot right).

Since I've deleted half a dozen attempts here trying to define exactly what I mean with a "builder", I'll instead try to point out what I liked best in Prison Architect:
- The ability to be clever with architecture - efficient walking routes, barriers, shortcuts, things like that.
- Being able to fix problems on the fly (e.g. provide extra entrances to reduce crowds).
- Quickly designating entire "zones" for a purpose:
- I particularly found it very satisfying the way you can drag-select a large area to be a building, and then fill in the details within that building later, but not being limited by this.
- Being able to "pause" for detailed planning, with the game offering some form of support for this which doesn't cost you anything.
- Remodeling being possible, but not happening instantaneously, meaning that you have to plan alternative solutions for while the remodeling is happening.
- Challenging without being crippling: You can make costly mistakes at any point in the game that'll really make you curse and think about loading a save game, but still recover from them.

I love Caesar, Pharaoh + Cleopatra, etc, as well as Tropico and Settlers and Banished and so on, but I'm not looking for something on that scale, nor - I think - with much in the way of production chains.

I love Planet Nomads, but I'm not looking for something where you build one "block" at a time , plus it's more an exploration game than a building game (or at least, I would want the game to provide me more of a goal with building). (Idem for Infinifactory wrt "one block at a time", plus that's more a puzzle/optimization game than a builder.)

The games I'm currently eyeing most seriously:
- Parkitect - I fear it might be too much about building individual rollercoasters, and not enough about building the park as a whole? Also, two DLCs already, and anemic discounts, which has been hampering me taking a chance on this, though I guess I'm going to at some point anyway. Is this what I'm looking for?
- Megaquarium - Not very fond of the art-style - it feels pretty 'sterile'? Also not certain if it has enough going on to be an interesting challenge?
- Rimworld - Too much chaos, too much micro-management, not enough control, not enough chances to be clever and build neat solutions?
- Factorio - Too grand a scale, too convoluted; why do I keep lusting after this anyway? (Okay, something I just want - but I really don't think it'd scratch this itch. Or would it?)

I'm looking for alternatives whose existence I might've missed, or pointers from personal experience that these games do or don't scratch the right itch.

For me, the game must be DRM-free (ideally available on gog), and must run on Linux (preferably natively), but feel free to recommend games that don't fit those criteria - I like being aware of what else is out there as well.

So in what way does SimCity 2000 or SimCity/Micropolis not match your quantification here?

Have you tried Frostpunk?

Also, since you like Factorio, you should check out Dyson Sphere Program & Satisfactory.

And this isn't really a builder at all, but I would recommend something like Cities in Motion. It requires tons of planning, route management, finance tinkering, and all sorts of stuff. The game also just oozes charm. Hopefully it's not too far off the path you're looking for.

Your eye's on Rimworld. Do it. The game pauses, and you can adjust the events/enemy/"chaos" to your preference. Clever building is important for defenses. You also mentioned 'zones' -- this game work with that.

Parkitect: The whole park matters. You can't succeed well on just a perfect coaster.

First and foremost (though it's a bit light on the builder elements to be fair)
Startopia - legendary space station sim where you renovate a derelict space station to attract a variety of quirky alien visitors, both for work and pleasure. I seem to recall it working without a hitch on widescreen resolutions.

Or how about some of the classics that have gotten some modern attention to get them working properly on newer systems:
openrct2 - you can build rollercoasters if you want, but you really don't have to since there is a plethora of rollercoasters of each type to select from.
openttd - you build transport networks, and decide how complicated you want to make it. Anything from a single railroad track from a coal mine to a power station, to massively complicated webs of railroad intersections used by scores of trains to transport of a variety of good to/from factories are viable (provided you set up the rail signals correctly). Not to mention busses, trucks, ships, planes and helicopters are also available, and you can see towns&cities grow in response to the accrued benefit of your transport network.
Theme Hospital - the one and only, though I hear that Two Point Hospital is a very competent spiritual sequel.

And if you liked Caesar and the rest of the Impression Games city builders then you'll probably also enjoy the anno series from 1602 right through to 1404 at least.

Or you could go the hardcore route and dive down the DF rabbithole and lose weeks of your life :P

Finally, Rise to Ruins - haven't played it myself, but it looks very promising.

this!

Edit: theres also its moddability.

Additionally, you could give Factorio a look. A different kind of builder, but...

Edit2: oh you mentioned that. Like Rimworld you can scale things to your liking and mod it to hell. Its actually very addictive (and I think theres still a demo on the games website).

anno 1800 , clearly the best city builder

This is true to an extent. It is a builder, but not in the traditional sense, I suppose. It has one helluva story campaign though. Short and sweet.

Ah, I'd meant to name them in relation to loving the "zoning" in Prison Architect. They fit very well indeed, though lack, perhaps, a bit of challenge? But mostly, I'm looking for something I haven't played yet. :) I don't know yet if I actually like Factorio. I just lust after it. Frostpunk, like Darvin mentioned, isn't really what I'm looking for here (though it certainly has my interest - sadly the Linux situation is rather iffy). Cities in Motion I've looked at, and discounted due to lack of Linux support (here) and bad rating, but I'll give it a second look. The other two I don't know, but will investigate. Thanks! Very helpful, both comments! Not loving my initial look, but I'll spend a bit more time investigating. I think I played the original, and didn't love it. One of the reasons I'm a bit hesitant about Parkitect. Should've mentioned this; love it and return to it regularly, though it's been kinda sorta replaced for me by Transport Fever, maybe? I think that's helped me clarify another thing I enjoyed about Prison Architect, and could be looking for again: an empty map that you shape yourself, not a world that you inhabit. (Strike against Rimworld and possibly Factorio there.) Sadly I really don't like this theme either. I have three of the anno series; I've only played one, and enjoyed it, but was badly punished for being too greedy, needing to backtrack waaaay too far to keep my colony viable, so am taking a break until the sting of that has faded and I can start over with fresh eyes - but they're not what I'm looking for here; both due to scale, production chains and "empty map". Oh, I've contemplated it, believe you me! But no. :) Definitely try it - it's great, and based on your suggestions, I suspect you'll love it just as much as I do! (But again, too much map/scale/chains to be a good fit here.)

Thanks to all of you, and also Sachys, Orkhepaj and Darvin for the reinforcement and counterpoints!

Space Haven?

I know this very skilled bloke a few streets away, called Bob. He's pretty handy round some materials and a few tools. I can pass on his number, if you're interested... :p

They Are Billions is pretty good, if you don't mind building to prepare for a tower defense kind of event where zombies storm your base. It can be fun, frustrating or both! I've enjoyed it to be honest and hope we'll see more games like it.

It runs well on Linux with Wine (Staging) and preferably DXVK to get around some graphical glitches in WineD3D.

If you want an isometric "Dwarf Fortres little" but not so little. Try Gnomoria.

If you want something newer, but work in progress, try Songs of Syx. It is very promising high scale builder game and pretty complete in its current state, it will be even better, I smell it.

Take a look at Mindustry, which is currently free on itch.io. It's something like Factorio with tower defense. I haven't played it yet, but I've heard a lot of people praising it and the reviews are Overwhelmingly Positive on steam.