Yokoi was moved from maintenance to the new "Nintendo Games" department as a product developer.Nintendo continued to produce popular toys, including the Ultra Machine, Love Tester and the Kousenjuu series of light gun games.
He found that the biggest playing card company in the world was using only a small office.
Yamauchi's realization that the playing card business had limited potential was a turning point. However, Nintendo was forced to sell it because problems with the labour unions were making it too expensive to run the service.
Nintendo of America president Minoru Arakawa managed a deal to bundle the popular third party game Tetris along with the Game Boy, and the pair launched as an instant success.
In 1989, Nintendo announced plans to release the successor to the Famicom, the Super Famicom.
He worked for Yokoi, and one of his first tasks was to design the casing for several of the Color TV-Game consoles.