Which developer partnered with Game Freak to make Pokémon Pokopia?

Omega Force partnered with Game Freak to develop Pokémon Pokopia.

Omega Force is a development group within Koei Tecmo, and it was selected because of its experience with sandbox-style games. Game Freak, the long-standing Pokémon developer, brought its series knowledge to the project, while Omega Force contributed experience suited to building and open-ended environmental interaction.

The partnership is especially notable because Pokémon Pokopia moves away from the traditional structure of catching, battling, and progressing through gyms. Its design emphasizes construction, cultivation, habitats, and social simulation. The game’s development history also identifies Dragon Quest Builders 2 as an example of the type of sandbox work that helped make Omega Force a suitable partner.