Press Square, Triangle, Down, Left, Up, Right, L2, R2, Start at the "Press Start" screen. Note: You cannot save the game when this code is enabled.

Ishani (Business outfit)
Ishani(Retro silver foil outfit)
Dwayne (Mullet outfit)
Dwayne (Purple and green superhero outfit)

Complete all songs in Showtime mode to unlock cheat options such as Big Eyes, Different Mics, Small Head, etc.

Complete all songs in Showtime mode with all "Gold" ranks to unlock cheat options such as Big Head, Glass Character, etc.

Complete all songs in Showtime mode with all "Platinum" ranks to unlock cheat options such as Tough Crowd, Pirate Crowd, Zombie Crowd, etc.

The bonuses include The Dude, Helga, Sorrow, Vox, and Joe as playable characters; multiple alternate costumes for Ishani and Dwayne; The Garage, The Wagon Wheel, and HMX Records locations; Rich Girl, I've Got You Under My Skin, and Virtual Insanity songs, and the Wavegroup Sings, Harmonix Sings, Playtesters Sings, and Konami Sings FMV sequences.

Enter one of the following at the start screen:

Unlock GamePro t-shirt:
DOWN, R3, UP, R3, L3, DOWN, L3, UP, DOWN, SQUARE

Unlock GameStar t-shirt:
UP, R3, RIGHT, R3, R3, LEFTt, R3, DOWN, CIRCLE, CIRCLE

Unlock Harmonix t-shirt (Ishani):
L3, CIRCLE, UP, CIRCLE, SQUARE, L3, DOWN, DOWN, R3.

Konami T-shirt (Dwayne):
RIGHT, R3, RIGHT, R3, SQUARE, RIGHT, CIRCLE, SQUARE, DOWN, LEFT.

Game Informer t-shirt (Angela):
DOWN, L3, L3, R3, R3, CIRCLE, RIGHT, SQUARE, L3, R3

Beat the game with any character on single play showtime mode and get all Platinum records. You'll get:

Rich Girl
I've Got You Under My Skin
Virtual Insanity
The Garage
The Wagon Wheel
HMX Records
Wavegroup sings
Harmonix Sings
Playtesters Sings
Konami Sings
Wavegroup