Pokémon Stadium series
The Pokémon Stadium series was a spin-off series of Pokémon games released during Generation I and Generation II and compatible with the games of those generations. In the games of this series, players can upload Pokémon from their Game Boy games to battle in 3D in various modes, most notably Stadium Mode, featuring various classes for Trainers to beat, and the Gym Leader Castle, featuring the Gym Leaders, Elite Four, and Champion of the respective generation's games.
There are three games in the series
When Generation III was released, many expected a third (fourth in Japan) Stadium game to surface, complete with a Hoenn Gym Leader Castle. However, this was not meant to be, and instead players were treated to two RPGs, Pokémon Colosseum and Pokémon XD, and a separate storage system, Pokémon Box Ruby & Sapphire. In the most basic sense, the Stadium series had ended. However, in the fourth generation, Pokémon Battle Revolution brings back many of the features of the Stadium series, such as Little Cup, the division to rounds and prize Pokémon. However, there is neither a Sinnoh Gym Leader Castle, a storage system nor a mini-game mode.