Increase Game Boy Tower Speed
Successfully complete all cups in stadium mode or defeat either Gym Leader Castle in Round 1 to unlock the Doduo sticker for the GB Tower, allowing you to play Pokémon Gold/Silver at double speed. Successfully complete all cups or defeat the Gym Leader Castle in Round 2 to unlock the Dodrio GB Tower, allowing you to play Pokémon Gold/Silver at hyper speed.

Alternate Title Screens
Successfully complete all cups in stadium mode to unlock a different title screen. Successfully complete all cups in Round 2 to unlock another different title screen.

Rival Cup
Successfully complete all cups in stadium mode and defeat all trainers in the Gym Leader Castles to unlock a special Rival Cup in the lower right hand corner of the main map. Select it to fight against Mewtwo, Ho-oh, and Lugia.

Rare Pokémon
Successfully complete the Rival Cup in Round 1 to unlock a rare Farfetch'd with the Baton Pass. Successfully complete the Rival Cup in Round 2 to unlock a Gligar with the Earthquake move.

Harder Mini-Games
Challenge the computer to a mini-game battle on the hard difficulty setting and win the game to unlock the super hard difficulty setting.