Secret Levels:

Cave of Bad Dreams Level:

Needs: The name from Clark (get it at the end of level 6:The Menhir Hills)
Location: Huge tree (jump from the Lilly pad) at the beginning of level 3
Prize: Yes-Coins and Island No-Life Potion.

Walk of Life Level:

Needs: 60 Yellow Lums
Location: The Bayou(Look on your left)
Prize: 100% Health.

Walk of Courage Level:

Needs: 450 Yellow Lums
Loc.: Santuray of Rock and Lava (Look on your left)
Prize: 3 Power Fists.

Giant Rayman:

On Level 16: Tomb of The Ancients close to the end you'll end up in a room with a very strong robot, a broken post, a barrel thing, a net on one wall, a purple lum, and a set of stairs leading to a barricaded room. After destroying the robot go up the stairs and to the left you'll get on the purple lum (you have to jump.) Do not get on the net. Turn and jump on top of the stump. Get on the edge so that it looks like you are standing on air and press Z.