Enter these initials at the high score screen to get the cheat effect.

Password - Effect

KTT - Beer turns bubbles into pizza at end of level
YSH - Coke can, sunflowers turn enemy into diamonds
KIM - Coke can, sunflowers turn enemy into diamonds
NSO - Coke can, sunflowers turn enemy into diamonds
MTJ - Coke can, sunflowers turn enemy into diamonds
I.F - Coke can, sunflowers turn enemy into diamonds
STR - Flamingo turns bubbles into smiling droppings at end of level
... - Knives, cakes, vegetables turn enemy into diamonds
TAK - Octopus turns bubbles into Xs at end of level
SEX - Pitch forks, cakes, vegetables, and other items turn enemy into diamonds