Rayman 3D

At the "Access Denied" screen that appears after you beat a level without collecting all cages and lums, input this button sequence. The word CHEAT should appear on the screen underneath the words ACCESS DENIED.

In the last area in Tomb of the Ancients, on the dark spot n the third panel behind the "Technical Check-Up" door, press the buttons "B, Y, D-Pad Right, D-Pad Left, D-Pad Right, D-Pad Left" in that order. If you were in the right place when you entered the code, a crate will appear that allows you access to a hole in the wall. In this hole, you can view various secrets about the game.

On "The Crow's Nest", fly towards the highest point of the roof you can, aiming to hit the center. Keep holding the B and Y buttons until you hit it. If you aimed right, you should be teleported into a metal pipe structure. Get to the end of this metal pipe structure and you should be teleported back to the main area. The orange balls of ammunition that you can normally obtain should have turned blue, and will now never run out unless you get hit.