Star Wars: Republic Commando Cheats

Just clear the Geonosis campaign level.

In the Wookie level hanger, enter a gun turret. Use the Left Analog-stick to slowly move the turret around the hanger. You can even take it off the edge of the platform. You cannot fall off, even when you get out -- you will return to the platform.

Unlock Temuera Morrison Interview:
Clear the Kashyyyk campaign to unlock an interview with Temuera Morrison (Actor who played Jango Fett in the movie).

Restore Ammo:
While playing, press Sart to pause and enter Y, Y, DOWN, R-Trigger, L-Trigger, R-Trigger, Up to refill all the ammunition of #38's current arsenal.
Unlock Foley Featurette:
Clear the Geonosis campaign.

Unlock Spec Ops Featurette:
Clear the Assault Ship campaign.