Pokémon Stadium (1999)

In the game's Stadium Mode, one player competes in 80 different battles, divided into four tournaments. Beat the Stadium Mode and you're in for a bonus battle against the ultimate Pokémon warrior, Mewtwo, as well as a secret mode that gives you 80 brand-new, and devilishly tough battles. There is virtually no way you can beat the secret mode without having trained your own, elite Pokémon. One to four players compete against each other or the computer in a no-holds-barred battle with customizable rules. You can select rental Pokémon for these battles -- but that makes them much too predictable since their selection of techniques isn't determined by the trainer. You can also select quick and easy versus and random battles.