The Abyss

Description
The red sky world is a world full of monsters and the home world of many girls that you found in the game, is stated that the world actually doesn't have a name, but there is a few different things between our world, like having red sky, having flora with other predominant colors, having two moons, doesn't having the dinosaurs being extinct and of course, being inhabited mainly by monsters.

Some of the inhabitants of this world are
 * Arachne
 * Centaurs
 * Demons
 * Dragons
 * Giant Hornets
 * Kasa-obake
 * Kitsune
 * Lamia
 * Mermaids
 * Nekomata
 * Ranari
 * Raptors
 * Slimes
 * Typhon
 * Yuki-onna

Map
There is a map with the political landscape of this world. Some of the nations are
 * Typhon's Empire
 * Empire Colonies
 * Frozen Land of Spirits
 * Dragonlands
 * Leviathan's Domains
 * Golden Kingdom

Political Issues

 * Ai says in her concert that the Slime King is coming after the Frozen Land of Spirits to feast on every citizen.
 * The Typhon's Empire, What is left of the Empire, The Dragonlands and The Frozen Lands of Spirits are joining forces to stop the attack from the humans to their world.
 * The Nobility of the Empire is becoming independent of the Emperor because of the senility of him, creating different nations insides the country's territory.

Technology
It's stated by Eydís Níðhöggr that her world is well developed in plasma and energetic tech, but they lack the science and technological development of our world, they haven't reached any other planet (or even know about other planets) and they haven't developed long-distance communication. They seem to rely more on the racial capabilities of each individual more than in tools and weapons.

Trivia

 * Womp is a way to greet someone in the Swamplands
 * Most of the world is based on Japanese culture
 * They have holograms