To enable the following in-game cheats press 'Start' when you select a mission and then go to the 'Extras' option and enter the code for the effect you want to unlock by turning the dials.

Unlock Dark Heroes:
Enter Cannonbolt, Cannonbolt, Fourarms, Heatblast.

Unlock DNA Force:
Enter Wildvine, Fourarms, Heatblast, Cannonbolt.

Unlock Invincibility:
Enter XLR8 ,Heatblast, Wildvine, Fourarms.

Unlock Alien Forms:
Enter Wildvine, Fourarms, Heatblast, Wildvine.

Unlock ALL Locations on Map:
Enter Heatblast, XLR8, XLR8, Cannonbolt.

Unlock ALL Combos:
Enter Cannonblot, Heatblast, 4arms, Heatblast.

To access the master control for the in-game cheats press 'Start' when you select a mission and then go to the 'Extras' option and enter the code 'CannonBolt, HeatBlast, WildVine, 4Arms'.