When you are at the screen where the choices are START GAME or OPTIONS, go to options, then PASSWORD. Insert DLVTRKB, then one of the following:(Repeat the steps above after and insert
another code.

BRD Bird mode(UP+SELECT+A turns it on or off)

LVL Level select(In PAUSE, hit A+B and it shows the current level. Hit left or right to select level

LVS Infinite lives

NRG God Mode

WPS Infinite Ammo