there are universes, they are like sheets of paper superimposed on each other, their structure is not uniform, where the sheets are in contact with others, somewhere on the contrary they diverge to form a subspace.
on the sheet of this universe, under the endless white sky, where there is not a single luminary, in the black endless sea, reminiscent of a swamp, bubbles of worlds have emerged, just as black, absorbing light.
But this world is not empty, here, in a black swamp, there is an endless battle between shadows and spirits.
be careful when walking along one of the safe paths, both of them may think that you are superfluous here.

each of the bubbles of the worlds has its own properties, some are easy to get into, while others will have to tinker with, looking for doors and breaking locks, bypassing guards and traps. Some can be full of holes like a sieve and gradually turn into a part of the surrounding landscape, disappearing forever, some, on the contrary, suddenly emerge from oblivion.

inside, the bubbles are divided into three types. Plan, Peace and Space. There are worlds that are so unimaginable that it is extremely difficult to classify them.
plan-type worlds are extremely uniform
it is a flat disk of land on water or some other liquid, the sky of which is the shell of the world. You can also see the stars and the sun on this shell, but they will be nothing more than a change in the structure of this shell, and not separate objects. The plan can be huge, containing an incredible variety of biomes and different peoples. Or maybe a small piece of dry desert, containing a dilapidated building, from the memories of a demiurge.

plans often live extremely shortly as they are not balanced and require constant replenishment, but there are exceptions.

world type world.
As paradoxical as it may sound, it is easiest to compare it with the solar system. These are several balls or islands that are suspended in the air, if the stars here are still either amorphous objects or small objects, then the star can already be touched.
The laws of physics are different everywhere, so you can, once in this world, how to start suffocating from being in a vacuum, and calmly fly or even float in space. Of course, such worlds are often many times larger than plans.

world like space
the rarest and most complex type of worlds. This is a full-fledged structure, which is extremely difficult to penetrate, here you may encounter even more unusual phenomena. In this type of worlds you will no longer find drawn stars, you will feel all their power and size, you can even see other worlds inside the world. Perhaps it will be space with universes and galaxies. Perhaps it will be a tree on which residents freely walk, passing from one world to another, or maybe this is a huge sea, where cities are built inside huge fish. You won't be able to find out about it until you get inside. Such worlds live extremely long and never appear by chance. They can only be created by demiurges.