Type during gameplay:

Down on analog + Down on D-pad + X.-Polska 
Down on analog + Down on D-pad + A.-Heavy breathing 
Down on analog + Down on D-pad + B.-Rude mode 
Down on analog + Down on D-pad + Y.-Side scroller mode 
Left on analog + Down on D-pad + X.-Mega head 
Left on analog + Down on D-pad + Y.-Stumpy 
Left on analog + Down on D-pad + B.-Clodhopper 
Left on analog + Down on D-pad + A.-Team God mode 
Up on analog + Down on D-pad + X.  -Big head mode 
Up on analog + Down on D-pad + A.  -Avatar God mode 
Up on analog + Down on D-pad + B.  -Victory Condtions 
Up on analog + Down on D-pad + Y.  -No brainer