Globox Disc Access multi-player mini-game: 
Press Start, then hold L + R and press B(4) at the title screen. 

Map bonus at the end of a level (Raycap): 
Press A, B, X, Y, X, Y before the "Access denied" message appears. 

Kaleidoscope textures:
Press Down, A, Down, B, A, Y, X(2). 

Rayman VMS icon:
Press Up, X, Y, Down, Y, X, Left, Right. 

Hidden passage:
Press A, B, X, Y, X, Y in Morb_20 (second section of the spider level). A secret
passage that reveals cheat codes to get full powers will appear. 

Full life:
Tap R repeatedly in a constant rhythm. Note: Vary the speed until it works. 

Full pause screen:
Pause game play, then press X + Y.