Cheat mode
Enter one of the following codes at the "Secret Cheat" screen to activate the corresponding cheat function. 

Master Control
Enter Cannonbolt, Heatblast, Wildvine, 4Arms as a code. You can now go alien to alien with no timer. 

Dark Heroes
Enter Cannonbolt, Cannonbolt, 4Arms, Heatblast as a code. Your appearance will now be darker. 

DNA Force
Enter Wildvine, Fourarms, Heatblast, Cannonbolt as a code. Your appearance will now be translucent. 

Invincibility
Enter XLR8, Heatblast, Wildvine, 4Arms as a code. 

Alien forms
Enter Wildvine, 4Arms, Heatblast, Wildvine as a code. All five alien forms will now be unlocked. 

All combos
Enter Cannonbolt, Heatblast, 4Arms, Heatblast as a code. 

All locations on map
Enter Heatblast, XLR8, XLR8, Cannonbolt as a code.