During play, type in the following codes and press Enter to activate:

boxes		Collision boxes around objects    
clearc		Clear caches      
diags		Display diagnostic   
dload 		Return to windows 
fly		Flight mode       
getalife	Unlimited lives   
goto		Level skip        
normal		Normal game speed 
pede		Create centipede   

report		Generate report	files
robot		Auto firing & movement until player takes control     
showz		Screen modes      
slow		Slower game speed  
sloww		Even slower game speed 
slowww		Even slower than above       
slowwww		Incredibly slow    
times		Time codes        
wimp		God mode          

Thanks to Revolution reader Mike Scott!