Star Wars The Force Unleashed 2 - Unlockable Costume Guide [360-PS3-PC]
Here's what needs to be done in Star Wars the Force Unleashed 2 is to unlock the bonus additional costumes:
City General: get a silver medal in the "Deadly Path Trial" challenge.
Saber Guard: get a silver medal in the "Cloning Spire Trial" challenge.
Terror Trooper: get a silver medal in the "Terror Trial" challenge.
Experimental Jedi: Complete the game with the "Light Side" ending
Dark Apprentice: Complete the game with the "Dark Side" ending
this if you are loyal to your duty as a gamer and want to get the costumes without using tricks.
If, on the other hand, you don't give a shit and want to do it first, then take a look at the cheat codes for this game in the dedicated guide. You will find those to unlock costumes and more.