What was the first Pokémon game pair to receive a worldwide simultaneous release?

Pokémon X and Y were the first Pokémon game pair to receive a worldwide simultaneous release.

The two Nintendo 3DS games launched on October 12, 2013, in Japan, North America, Europe, Australia, and other markets. Earlier main-series Pokémon games had generally appeared in Japan first and reached international markets months or years later.

A coordinated launch helped make X and Y a global event and reduced the long wait that international players had experienced with previous generations. It also reflected the increasingly worldwide audience for Pokémon games, anime, cards, and merchandise.

X and Y were sixth-generation role-playing games set in the Kalos region. They introduced 72 new species, Fairy-type Pokémon, Mega Evolution, character customization, and fully 3D polygonal graphics. The simultaneous release date is separate from the games’ announcement date, which was January 8, 2013.