What is the name of Pokémon Pokopia’s underlying game technology?

Pokémon Pokopia’s underlying game technology is called Katana Engine.

Katana Engine appears in the game's technical credits as its engine. In video games, an engine is the underlying software framework that helps manage areas such as rendering, physics, input, world systems, and other technical functions needed to make the game run.

That technology supports Pokopia's distinctive design. The game lets players alter environments, construct objects, cultivate habitats, and attract Pokémon whose preferences differ from one another. It also presents several biomes and a real-world-linked day-and-night cycle, all within a social-simulation framework.

The name is easy to misidentify because Pokopia was co-developed by Game Freak and Omega Force and published by Nintendo and The Pokémon Company. Those companies describe who made or released the game; Katana Engine describes the technology listed for the title. It is also not the name of a fictional region, Pokémon, or expansion.