Which Nintendo 64 game first presented Pokémon in fully 3D battles?

Pokémon Stadium first presented Pokémon in fully 3D battles on the Nintendo 64.

The game was developed and published by Nintendo and released in Japan in 1999, followed by Western releases in 2000. It centers on turn-based battles displayed with three-dimensional models, announcer commentary, and several tournament-style cups.

Pokémon Stadium connected to Pokémon Red, Blue, and Yellow through the Nintendo 64 Transfer Pak. This allowed players to bring compatible Pokémon from Game Boy cartridges into the Nintendo 64 game. Players could also use rental Pokémon, so the game did not require a Game Boy save file.

Pokémon Snap is sometimes named instead because it also used 3D Pokémon on the Nintendo 64. Snap, however, is a photography game rather than a battle-focused stadium title. Pokémon Stadium’s Western release supported 151 Pokémon from the original Game Boy generation, although only 40 were directly playable in its battles.