Dream world of horror

The Iznanka is very similar to Earth, with one exception: the sky is either red (morning/afternoon) or completely black with rare "stars" (evening/night). In the Iznanka, the Moon, the Sun, and the stars can be alive and cannot be trusted. The Moon is a huge eye floating in space. If there is a full moon, people (those few unfortunate souls who find themselves in the Iznanka) are better off not looking at the Moon, lest they become part of it. A partial moon is the most common occurrence; for the inhabitants of the Flip Side, it's as normal as a blue sky is for us. During a red moon, people may not survive, as the inhabitants of the Iznan'ka become less friendly. The Sun works strangely: it's either black or white, it can be too high or too low, it can be enormous or very small. Sometimes the Sun simply disappears for a few hours and then returns. The inhabitants of the Iznanka are used to this and don't pay much attention to it. "Stars" are not the usual stars, but the eyes of a giant creature, so "stars" are a very rare phenomenon in the sky of the Iznanka, but the inhabitants of the Iznanka treat this as people treat the ocean or space. Clouds can be alive and some black clouds can have eyes. Moreover, the inhabitants of the Iznan'ka themselves do not know that they are created from human fears, because for them it is the world and they are absolutely real, if a person tries to explain this to someone, no one will believe him. At the instinctive level, all inhabitants of the Iznanka are attracted to human fear. Not all the inhabitants of the Iznanka are friendly; most of them are neutral towards people or will try to hunt.

The Iznanka has changed in response to people's fears. Previously, it was a predominantly wild place, but with the advancement of technology, the Iznanka has become a more diverse place. There are places ranging from simple Dark Forests to entire Living Cities, where the buildings are living, fleshy creatures with their own feeding habits, digestion systems, and so on. In some places, the geometry may differ—for example, a room or corridor may be wider and longer than it appears on the outside—and for the inhabitants of the Iznan'ka, this is completely normal because they've been living with it for several years.

The inhabitants of the Iznanka are very diverse, as they were created based on human fears, or perhaps had such ancestors. Some the Iznanka inhabitants look like severely deformed humans, others look like distorted creatures from human cartoons, and this is absolutely the norm. In the Iznanka, there are creatures like Tarball, Heros, and others, their appearances are distorted, but they themselves don't know who Gumball or Finn are, as they are separate beings and live in a different reality. Due to the diversity of fears, phobias, analog horrors, ARGs, and so on among humanity, the forms of the inhabitants of the Iznanka are also diverse.

Since the inhabitants of the Iznanka were created based on human fears, or had such ancestors, their culture and morality may differ. For example, biting someone can be a greeting, biting off half a head is the equivalent of a slap in humans, and some tearing off their own eyes and sharing them is the equivalent of trust or "look how beautiful." Their smile has a slightly different meaning than that of humans, as some creatures lack cheeks or have faces designed to always smile. If the smile is ordinary, slightly grotesque, it's okay; if it's toothy, it's an expression of interest and involvement; if the smile reaches the ears or eyes, it's a sign of hunting and not friendliness at all, even if creatures with such a smile will say there's nothing to fear. At the same time, there is a difference between "biting the head in a friendly way" and "trying to kill"; this can be expressed in blows with claws, gnawing the body down to the bones, and so on, because if there is no flesh left on the bones, then regeneration will not occur. Because of this culture, it is very difficult for a person to understand which creature does not wish him harm and which one wants to kill.

There's technology in the Iznanka, too, but while it may look like human technology, it's very different. Telephones, computers, and televisions can be made from living mold, from the organs of other creatures/people, or even grown in a flask. In the Iznanka, there are builders (these are separate creatures resembling tower cranes), scientists, and so on. The Internet in the Iznan'ka is a vast underground network of fungus/mold, yet it contains everything: websites, entertainment, platforms, and so on: Nexel - a YouTube analogue; Flicker - a TikTok analogue with short videos; Voxis - a Twitter/X analogue; Hive - a Reddit analogue; Viora - an Instagram analogue; Nexus - a Discord analogue; Astra - a Wikipedia analogue.

Transport...only the very rich can afford fully living machines, as they're no longer just "vehicles" but fully functioning living beings that require care. However, such vehicles are completely autonomous and don't require a full-fledged driver. The inhabitants of the Iznanka primarily use biomechanical transport; it's cheaper and doesn't require the care of a living being, but it does require a full-fledged driver.