One on One Cheats for PlayStation
Unlock Art Gallery:
Finish the game and the Art Gallery will become unlocked.
Unlock Dr. T:
To unlock Dr T start a new one player story mode game and find him.
Unlock Oscar and Mash:
To unlock Oscar and Mash start a new one player story mode game and find them.
After you have completed the game with every character including Oscar and Mash you will unlock King.