The first Pokémon games, Pokémon Red and Green, were released for the Game Boy.
Nintendo's monochrome handheld was the original home of the Pokémon role-playing games in Japan. Despite the system's limited display technology, the games created a large world in which players could explore, battle, trade, and complete a Pokédex.
The Game Boy's link cable was especially important. It allowed players to trade Pokémon between separate game cartridges and battle one another, making collecting more than a solo activity. Some Pokémon could only be obtained by trading between game versions, encouraging players to connect with friends.
Pokémon later appeared on the Game Boy Color, Game Boy Advance, Nintendo DS, Nintendo 3DS, Nintendo Switch, and mobile devices. Those later platforms are sometimes associated with the franchise's early years, but the original Japanese games were Game Boy titles.