We have 1 cheats and tips on PlayStation. If you have any cheats or tips for One on One please send them in here. You can also ask your question on our One on One Questions & Answers page.
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.
Unlock King:
After you have completed the game with every character including Oscar and Mash you will unlock King.