Pokémon Strange Journeys: Make Room for Mash

Pokémon Strange Journeys: Make Room for Mash is a side-scrolling video game developed by Satsuki Game Company and published by 1happycats Interactive Media, and released on October 7, 2016 on Windows, macOS, Wii U and Nintendo 3DS. A Nintendo Switch port was released on April 1, 2017.

It is based on some of the first episodes of the third season of Pokémon Strange Journeys, and is the only game in the series to feature Mash.

Plot
Ash and Misty have given birth to a child they call Mash (Katoshi in the Japanese version), and somehow she had disappeared after two weeks. Misty orders Ash to look for her (Level 1), and it turns out that Team Rocket has captured her. Ash is forced to fight Team Rocket (Level 2) and successfully gets his daughter back.

However, Ash and Misty find that Mash has been behaving badly during her time with Team Rocket. After failing to make her go back to her old ways, Misty takes Mash to Entei (Level 3) and enlists the help of him to make her into an older child of six years old. Although Entei was able to age her, her behavior isn't that much different.