To kill a Droideka easily, stand as close as you can to it, and directly in front of it (between its gun arms). It cannot shoot you. Kill it with melee attacks to save ammunition. If there is more than one Droideka, stand so that you are in line with as many of them as possible so that the others cannot see you.
Defeating Greivious Guard
Use your EMP grenades and concentrate your men's fire on them. Once they are being shocked by the EMP, throw Thermal Detonators to deal extra damage. You should also use your DC-17's anti-armor attachment.
Defeating SBD's
Throw two electric grenades and fire a quick bust from the DC-17. This should shut them down or put them on the ground.
Free Electronic Disruption
Want to shock a droid for free? If you have a concussion rifle on hand, use its melee strike to stop and drop a droid in hand-to-hand combat. The shocking effect on droids is the same as if an electronic detonator was used.
Full Ammunition
Pause game play, then press Y(2), X, Down, R, L, R, Up. An explosion will confirm correct code entry. All current weapons will now be fully reloaded.
Ghost Ship Recon: Lightsaber
On the level where you first encounter the Trandoshan Elites (the ones with the minigun), just before you find the elite there is some debris you can blow up. Instead of doing this, turn right and crawl into the vent. Once you get inside, look behind you.
Ghost Ship Recon: Save ammunition
When you are on the ghost ship, you will not find any D-17 ammunition for awhile. Save it and spread all your ammunition around. You will get a shotgun type weapon during the game that is average, but not as good as the D-17. Also make sure that you have a sniper and ammunition for the droids.
Invincibility
Pause game play, then press Y(2), L, Up, X, Black, X, Y. An explosion will confirm correct code entry.
Restore Ammo
While playing, press START 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 and unlock the Foley Featurette.
Unlock Spec Ops Featurette
Clear the Assault Ship campaign to unlock the Spec Ops Featurette.
Unlock Temuera Morrison Interview
Clear the Kashyyyk campaign to unlock an interview with Temuera Morrison.
Walking turrets
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.