While playing a game, press [Shift] + [Enter] to display the console window. 
Then, enter one of the following codes to activate the corresponding cheat 
function:

Result - Cheat Code
1000 more credits - mo money 
One-shot kills - quicker than death 
Level skip - blitzkrieg 
Get units quickly - instant delivery 
Rank promotion for selected unit - smarten 
Display frame rate and polygon info [Note] - show fps 

Note: Only in version 1.3.