Go to any map after the first and enter the options screen. Select "Sound", highlight the "Mute" option, then hold L1 + R1 and press L2, R2, L2, R2, L2, R2. A cheat menu should appear.
Secret Multi-player Maps:
At the first map, enter the options screen. Select "Language", then select "Voices". Highlight the "Raymanian" option, then hold L1 + R1 and press L2, R2, L2, R2, L2, R2. Three more multi-player maps will be available.
Baby Soccer Secret Map Names:
Hold L1 + R1 and press L2, R2, L2, R2, L2, R2 during game play in Baby Soccer.