Type in the code (lower case) then hit the [-] key on the number pad

 bod             - Enable cheat mode
 bing            - Disable cheat mode
 dunky           - Highscore entry and back to main menu
 bucketofchicken - View from behind
 babapapa        - More credits
 bungle          - ???
 crystaltips     - 1 additional life
 albertofrog     - Super granades
 mrbenn          - Skip level
 zippy           - Infinite health
 triz            - Triangle info

 Start the game with one of the following command line parameters:

 -mumford              Hodspodkins Mode
 -whostayedlate        Rockhard Mode
 -whostayedlateagain   Easteregg Mode