During game play push the (START) button to bring up the pause menu and go down to (INPUT CODE). At this point enter the following codes to unlock costumes and force upgrades.

Password Effect

OSSUS All databank entries unlocked
EXARKUN All force push ranks unlocked
ADEGAN All saber throw ranks unlocked
JOCASTA All Talents Unlocked
RAGNOS Combo Unlock
PHOENIX. Incinerator Trooper.
MINDTRICK Makes levels mirrored.
FREEDON New Combo
MASSASSI New Combo
SAZEN New Combo
LUMIYA New Combo
PROTOTYPE Proxy skin code
BLACKHOLE Shadow-Trooper costume
SNOWMAN. Snow Trooper.
TK421BLUE Storm-Trooper commander costume
HURRIKANE Unlock all Lightsabre Crystals
MASTERMIND Unlock Emperor Costume
ADEGAN Unlock Lightsabre throw
MARAJADE Unlocks a New Combo
SOHNDANN Unlocks all 32 costumes
MOLDYCROW Unlocks All Force Combos
VICEROY Unlocks Bail Organa Costume
LIGHTSABER Unlocks Deadly Saber
TK421GREEN Unlocks Kashyyyk Trooper costume
KATARN Unlocks Maxamum Force Powers
DATHOMIR Unlocks maximum Force Repulse ranks
YADDLE Unlocks new combo
FERRAL Unlocks Scout Trooper Costume
SITHSPAWN Unlocks Sith Master difficulty
TK421WHITE Unlocks Stormtrooper costume
VENTRESS Unlocks the Aerial Ambush combo
EETHKOTH Unlocks the Aerial Assault combo
DANTOOINE Unlocks the Ceremonial Jedi Robes
BRUTALSTAB Unlocks the devastating Lightsaber Impale.
HARDBOILED Unlocks the DRUNKEN KOTA costume
HOLOCRON Unlocks the Jedi Adventure Robes
WOOKIEE Unlocks the Master Kento Costume "The Apprentice's Father"
MANDALORE Unlocks the Rahn Kota Costume
PLOKOON Unlocks the Saber Slam combo
KITFISTO Unlocks the Saber Sling combo
DARAGON Unlocks the Sith Slash combo
KORRIBAN Unlocks the Sith Stalker Armor

Unlockables

Jedi Robe Complete the game with "Jedi" ending
Sith Stalker Armor Get the Dark Side Ending