At the main menu when Abe says "AYYYBHHOOOOO" hold R1 and press up, down, left, right, square, circle, triangle, circle, square, circle, up, down, left, right
To make Abe invincible while playing press and hold R1 and press circle, triangle, square, X, down, down, down, triangle, square, X. just slap a Slig and see if you did it right. There is no sound to confirm this code.
During the game hold R1 and press circle, circle, X, X, square, square. This cheat will take you to the next significant portion of the game. Almost the next path. You can use the cheat as often as you like to get past difficult areas of the game. Note that using this cheat will result in less than ideal number of saved Mudokons and increase the number of killed Mudokons as a penalty for cheating, so use this code wisely.