DOTK: IIRC, the rock dispenser will only activate if you have a minimum amount of life.Known Glitches
Near the end of the first phase, the rock dispensing vending machine may not produce a rock, which is required to unlock the door to proceed. How this glitch is triggered is still not known: however, one way is to simply play the game without saving or turning off the console and when the user reaches this point, the glitch should have taken effect. The only known solution is for the user to reset the console and load the most recent save point they have.
Also in the longest shortcut a glitch exists where jumping into the the plate for the hidden room while it is spinning locks rayman in a black room. You can see his fists but you cannot escape or get back to the level.
In the summit beyond the clouds you can skip an entire section of the game. Can't remember exactly but you are on one side of the hill and you must make it to the other. Normally you go the the bottom and earn a blue power however with the right timing you can helicopter right over. Edit part two can be skipped
Also each level refers to a "murphy" score. What is this exactly?