Easy Mode:
Enter "WIMPIAM!" on the passcode entry screen.

Freeplay Code:
Enter "FREEPLAY" at the password screen to get free tokens for the arcade machine.

Unlock Arcade Game:
Enter RTJPFC!G, then TIMEWARP on the passcodes screen.

Unlock Art Gallery:
Enter "!KOOLART" on the passcode entry screen.

Unlock Asteroid Field For Co-operative:
Unlock the Asteroid Field for co-op play by entering RWALPIGC then NOWAYOUT

Unlock Black and White Mode:
Enter "NOCOLOR?" on the passcode entry screen to unlock black and white mode.

Unlock Credits:
Enter "LOOKMOM!" at the passcodes screen.

Unlock Death Star Escape Level in Cooperative Mode:
Enter YFCEDFRH as a password and accept it, then enter DSAGAIN? as a second password and accept it.

Unlock Documentary:
Enter "THEDUDES" at the password screen to unlock the documentary.

Unlock Jedi Starfighter:
To unlock the Jedi Starfighter, earn silver medals on all missions and bonus missions.

Unlock Music Hall:
Enter "HARKHARK" on the passcodes screen.

Unlock Naboo Starfighter:
Finish all of the Tatooine training missions during all four times of day by completing every objective and getting every hidden item.

Unlock Slave I:
Get bronze medals on all missions to unlock the Slave I.

Unlock TIE Advance For Co-op:
Unlock the TIE Advanced for co-op mode by entering VDX?WK!H and then ANOKSHIP

Unlock TIE Bomber:
Earn the TIE Bomber Canyon mission by getting silver on the Raid At Bakura. During the Bomber Canyon mission, destroy all of the floor turrets within roughly half a second of each other.
If you do not get a verbal thumbs-up from your wingmates for each batch of turrets, you should restart the level and try again.

Or, go to the passcodes screen and type in JASDJWFA and hit enter. Then type in !DABOMB! and hit enter. If done correctly, the TIE Bomber will appear in the back corner of the Home One hangar.

Unlock TIE Fighter For Co-op:
Unlock the TIE Fighter for co-op mode by entering MCKEMAKD and then ONESHOT!

Unlock TIE Hunter:
Obtain a gold medal on all missions to unlock the TIE Hunter in the hangar.

Unlockable: Jedi Starfighter:
First enter BBGMYWSX and R2 will beeb once. Then enter JEDIWHO? and R2 will beeb twice if done correctly.

Easter Eggs:
Death Star Rampage: See Darth Vader's TIE: In the Death Star Rampage level in multi-player mode, you can see Darth Vader's TIE fighter trying to shoot you down. It might take some time to find him. If you find Darth Vader, you can destroy him easily with a few laser shots or your secondary weapons.
Extraction From Ralltiir: Jedi Outcast reference: In the large area at the end of the AT-ST portion of the mission, there is a statue and a flame in the middle of the area. The orange platform on which the flame is resting has the Jedi Outcast lightsaber symbol on it.

Jango Fett's Slave 1: After unlocking Slave 1 and the Jedi Starfighter, play the Geonosian Asteroid Belt in dogfight with two Slave 1s. The appearance of one will change to Jango Fett's color scheme.

Hint: Easy Win on Defenders of Ralltir:
On the Defenders of Ralltir level, fly low and pick up the concussion grenades with your snowspeeder's tow cable. Fly over to a bridge, stay low, and let the bomb touch the brige. It will explode, and all enemies on it will be destroyed. This can also be used against Imperial AT-ATs to destroy them.

Tip: Training Mission:
Playing the training mission at all times of the day can take time and listening to the dialogue on every objective can be annoying. If you want to skip the text and just do the objective then touch the symbol, when the text appears on the screen and the voice begins just pause the game, then press start again to return to the game. Now you can just do the objective without having to wait.