Which Pokémon game gives the player Pikachu as the only starter Pokémon?

Pokémon Yellow gives the player Pikachu as the only starter Pokémon.

Released in Japan in 1998 as an enhanced version of Red and Green, Pokémon Yellow was designed to resemble the television anime. Instead of choosing Bulbasaur, Charmander, or Squirtle at the beginning, the player receives Pikachu from Professor Oak.

Pikachu follows the player around the overworld and reacts to the player’s treatment, reflecting its prominent relationship with Ash in the animated series. The rival starts with Eevee, and characters resembling Team Rocket’s Jessie and James also appear.

This does not mean Bulbasaur, Charmander, and Squirtle are absent from the game. They can still be obtained later through in-game exchanges and events. The distinctive point is that Pikachu is the player’s mandatory opening partner.