Older Cheats:
(last update - Jan 18 2001)
At the Title Screen, hold Z and press A, B, R, A (x2), B, R, A.
At the Title Screen, hold Z and press B, A, L (x2) to be able set the starting speed in marathon mode to a maximum of 99. You can also unlock this mode by scoring at least ten thousand points in the time zone.
At the trainer selection screen, hold L + R + Z on controller one and two to unlock the trainers marked by a "?". You can also unlock this by completing the Spa Service game.
At the Difficulty Selection Screen, hold Z and press L (x2), A, B to unlock the V-Hard difficulty setting. You can also unlock this by completing the game on the Hard difficulty setting.
At the Difficulty Selection Screen, hold Z and press R, L, A, B to unlock the S-Hard difficulty setting. You can also unlock this by completing the game on the V-Hard difficulty setting.
Select any two player game mode. Have one player select a character, then repeatedly press A.
At the trainer selection screen, hold Z and press B, Up, L, B, A, Start, A, Up, R to start the game in Mewtwo's stage. Player one will be Ash, player two will be Mewtwo. You can also unlock this by completing the game on the S-Hard difficulty setting.
Defeat one of the following characters to earn the badge:
| Character | Badge |
| Brock | Boulder |
| Misty | Cascade |
| Lt. Surge | Thunder |
| Koga | Sould |
| Erika | Rainbow |
| Sabrina | Marsh |
| Blaine | Volcano |
| Giovanni | Earth |
|
|