The game tracks the amount of time a user sleeps, using the accelerometer of the external Pokémon Go Plus+ accessory, and communicates the data to the user's mobile device via Bluetooth for sleep-related gameplay. Although the gameplay specifics have not been revealed, The Pokémon Company has promised it will turn "sleeping into entertainment" in a similar way to how the Pokémon franchise's other mobile games, Pokémon Go and Pokémon Smile, turned walking and oral hygiene into entertainment respectively.
It was apparently being developed by Japanese studio "Select Button", with assistance by Pokémon Go developer Niantic, and was going to be published by The Pokémon Company. It was announced on May 28, 2019 by Tsunekazu Ishihara, CEO of the Pokémon Company, during a press conference held in Tokyo as well as on the company's official Twitter page. The game was planned to be released in 2020, but while it has not officially been canceled, there have been no updates about the game's release as of 2022. However, an SSL certificate was registered in April 2021, which does raise the possibility it has not been canceled.