Pokémon Go launched in 2016 with approximately 150 Pokémon species.
The mobile game was developed and published by Niantic in partnership with Nintendo and The Pokémon Company. Instead of exploring a traditional game map, players used GPS and augmented reality to locate, capture, train, and battle Pokémon in the real world.
Its starting roster largely drew from the original first-generation Pokémon associated with the 1996 games. Later updates expanded the game with creatures from additional generations, regional forms, special events, and new mechanics.
The launch figure is commonly described as approximately 150 rather than as a perfectly fixed worldwide total, because availability and rollout changed across regions and updates. The original Pokédex contained 151 Pokémon, but Mew was not part of the ordinary initial encounter roster.