Pause the game, the press the following in order: C-up, C-up, C-up, C-up, C-up, C-right, C-down, C-right. It will say "Infinite Lives On."
Bonus levels
Press Start to pause game play then press C-Down, C-Up, C-Right(2), C-Down, C-Left, C-Right(2). Glover will cheer to confirm correct code entry. Several cheat codes will be displayed and all six bonus levels will be unlocked.
Code bird
Did you ever wonder what that weird looking bird is doing? Press B to hear a combination of sounds (fart, burp, hiccup, and bacaw). Press Start followed by C-Up, C-Down, C-Left, or C-Right to hear the same sounds. Try to match the series of sounds given by the bird to learn new codes. The name of the code will be displayed if entered correctly. This may be done every time a ball (crystal) is returned to the castle. Complete the game or enable the "Open Portals" code to receive new codes rapidly.
How to beat the gorilla in the desert island level
First you get the smaller annoying monkeys away by fist slamming them (a+z) then pushing them behind the the big rocks on the sides. ( you don't have to push them far behind the rocks.) Next, approach the gorilla. Be careful not to get too close or he will attack you. When he is swinging, time it just right and jump. Then, slap the ball at his belly after you do that he will swing really fast then he will swing off. After he falls of run to him and fist slam him he will get smaller and smaller untill he dies. (It takes three hits to kill him.)