NOTE: These are the main TMNT cheats that are usually applied by pressing down the right key combination. Please find the instructions on how to use these cheats below.

Cheat Codes
At the main menu, hold the [L1] button and enter any of the following code. After you have entering each code, release L1: you will hear a distinct comfiration sound if you have entered the code correcly.

[O], [Triangle], [X], [Square]: Unlock Don’s Big Head Goodie
[X], [X], [O], [X]: Unlocks Challenge Map 2

Oruginally from ActionTrip