The basic idea is a set of planes with latinish names -- these are themed but are pretty different from the way I normally do this kind of thing. They're associated with a color as well, which influences the stylesheet for the areas there.
Each plane has several small handcrafted locations, all of which are visible but not necessarily visitable.
Getting around from plane to plane requires inputting the right combination of astronomical symbols (Sigils), which is different from seed to seed. You find clues to story-progressive ones from other planes in a fairly linear way (though it does split occasionally). Some useful handcrafted ones are hidden and have to be found through some means of scanning the aether. There are also procedural ones, though they're somewhat rare.
Moving to a new one (whether there's something there or not) requires some kind of specialized fuel source. Moving to one you've already been to doesn't. However it does also take time in both cases, depending on its distance from your set of sigils, which also shift around in real time on the Sigilator, adding to the effect. This should max out at around 30 minutes.
Locations that have nothing can nonetheless be beneficial for Tempos (which is a hybrid buildable base and developable procedural world in its own right). You don't get these benefits while in transit, however, since you're just passing through.
Locations will have changes applied as you gather resources, fight things, buy things, etc. They can however be reset with Tempians, a rare-ish resource more common on Tempos than anywhere else.
The Portator will let you switch locations on a plane and enter it. Each area has one exit somewhere that goes back to Tempos.
Both of these devices are within the Odyssey Pod, one of the starting base rooms that's permanently rigged up for safe transit (more on this in the Tempos section).
Tempos -- where your base and Odyssey Pod are. Expandable, etc. It's a Luxic class, so can't be reset.
Granos -- your home plane and where the vast majority of humanity is, for good reason. You have no idea where this is anymore, but it'll be plot-relevant later on.
Platonos -- the plane you begin the game on. There's a gathering hall (for Amenti and some tutorial of shopping mechanics), a statues area (which you can't do anything with at first since the missing pieces are scattered all over. Not sure what they do yet either) and a sort of tutorial area to get a feel for combat and puzzles. Platonos is also Luxic class and can't be reset. There's enough plane fuel here to get to the next plane.
Venenos -- A toxic planet. There's a swamp, a jungle, a caustic lake and some kind of settlement. Somewhere in Platonos is a clue for how to get here, which is probably completely spelled out. It should only take a couple minutes from your starting location as well.
Aquos -- water-based. First things I'm seeing are a wide-mouthed waterfall area, a lake that isn't caustic, an ocean-like area and glass catacombs that are entirely underwater.
Salamos -- fire and heat based but very much alive.
Glacios -- ice based, has an unusually high number of subareas. I'm thinking Aquos unlocks both this and Salamos simultaneously.
Speluncos -- cave/earth/metal based.
Dryasos -- wood based but not in an ordinary way -- closer to my 4th book here.
Harenos -- desert type stuff
Machinos -- lots of machines, probably very late game
Kaos -- exactly what it sounds like. Lots of time based puzzles, also an unusually good source of Tempians.
Entropos -- incredibly dark and sort of swallows things up as well. One of the two planes that's ultimately responsible for the state of the universe.
Amentos -- incredibly bright and madness inducing. Very eldritch area and disorienting in all kinds of fun ways. Obviously you should unlock this and the above one simultaneously.
