You start out in something that's like an infinite void -- it isn't, there's stuff out here with better oxygen tanks, but that's what it practically is.
Anyway, this is where your starting base is, and you can expand it in an easy modular way.
To get to other parts of the world, you need to make Portals. You start out with one type you can make and then a specific resource there will metroidvania you into making new types.
Portals can be reset at any time by feeding them Aether -- this generates a new variation of that world type.
Portal Worlds
They're themed for sure.
They generate in a kind of semi-handcrafted way -- basically types of area tiles arranged in a progressive way with procedural variations.
There are various types of POIs that also spawn and are either open or lead to a different map.
Resources are handcrafted but pull a subset of a more broad list. You see what you get from the outset. An upgrade will allow you to see properties before generation and reseed if you don't like what you see (this does cost aether but not as much as generating the world). An even better one will allow you to adjust positive/negative properties to your liking with some upgradeable maximum.
