Ecco the Dolphin: Defender of the Future

At the title screen hold L1 + L2 + R1 + R2 and press following buttons:
Infinite health - Triangle, X(x2), UP(x2), DOWN
Unlock All Levels - UP(x2), DOWN(x2), Triangle, X(x2) to unlock all levels.
Infinite Air - UP(x2), DOWN(x2), Triangle, X and Circle to unlock infinite air.
All Vitalits - X(x2), Circle(x2), X, Circle, UP, DOWN(x2)
Swim with a group - X, UP, X, DOWN, X, Triangle

 