While in the game, type out "burgergod" to obtain invincibility. This cheat will activate/deactivate itself every time you type "burgergod".
Note 1: On level fourteen, you may have to type the cheat multiple times to activate it.
Note 2: You 'will' loose all your points when you use this code.
Note 3: During extended play, this cheat has been known to wear off after a couple of hours, but simply typing the code again will re-activate it.