Access multiplayer bonus maps:
     In the first map, in the Options Menu/Language/Voices, select the
"RAYMANIAN"  language (don't validate it), keep L1 + R1 pressed and do
the following sequence: L2, R2, L2, R2, L2, R2. A new menu will appear
with the three multiplayer bonus maps.

Other cheats:
     In  any other map, go to the Sound Menu, select the "MUTE" option
(again  don't  validate  it),  keep  L1  +  R1 pressed and do the same
sequence: L2, R2, L2, R2, L2, R2. A new cheat menu will appear.

Baby Soccer bonus map:
     During  a  game (before it ends), keep L1 + R1 pressed and do the
same sequence: L2, R2, L2, R2, L2, R2. The names of the players appear
on the baby globox.