Pocket Monsters Red and Green originally played on Nintendo’s Game Boy.
The Game Boy was especially important because its link cable allowed two players to connect separate systems. Pokémon used that feature for trading creatures and battling, turning a technical limitation into a central part of the game’s design.
The original Japanese games used monochrome Game Boy hardware, although later releases and related versions could also be played on compatible systems. Pokémon Yellow was designed with stronger visual links to the television anime and used the Game Boy Color’s palette when played on that hardware.
The Game Boy was already an established handheld by 1996, and its large installed audience helped Pokémon reach players across Japan. The system’s portability also matched the idea of carrying a collection of creatures and meeting other players to exchange them.