Pokémon Gold GAMEBOY

Pokémon Gold is Game Freak’s 1999 Game Boy Color sequel, set two years after the original games in the new Johto region while remaining connected to it — an internal clock tracks real-world day and night, affecting which Pokémon appear, and post-game content lets players travel back to revisit the original Kanto region on the same cartridge.

It introduces two new Pokémon types, breeding mechanics, and held items, expanding meaningfully on the systems established by Red, Blue, and Yellow rather than just adding new creatures to catch. Letting players revisit the entire original game’s region as bonus content after finishing Johto was an unusually generous amount of extra content for a handheld RPG at the time.