Ace Mode:
To get Ace Mode, win gold medals in all 15 missions.

Advanced Concussion Missiles:
The Advanced Concussion Missiles are in the tunnel across from the Spread Proton Bombs in ''Imperial Academy Heist.''

Advanced Laser Cannon Upgrade:
BATTLE OF HOTH: After the Rebellion's Shield Generator is destroyed by the AT-AT, the Laser Cannon upgrade will appear in it's place.

Advanced Proton Bombs:
In ''Ison Corridor Ambush'' there will be a large chunk of debris to your right when you start the mission. Go in the hollow tunnel to grab the power-up.

Advanced Proton Torpedoes Upgrade:
Right when you enter the second mission (Ison Corridor Ambush), dip down so you can see the piece of debris in front of you. It's hollowed out in the shape of a rectangle with the upgrade in the center.

NOTE: You must complete the mission after collecting the upgrade in order to keep it.

Advanced Shields Upgrade:
The Advanced Shields upgrade can be found in the first mission, Death Star Attack. After the cinema that leads into the second objective of the mission (killing the TIE fighters) continue going straight in the set path, only veer to the left a bit. Stay close to the planet surface and you'll find the rocket-shaped upgrade blended in with turrets and such.

Advanced Targeting Computer Upgrade:
In the ''Strike at the Core'' mission, in the last tunnel before you actually reach the core (you'll know it, it's right after the inclined sections. If you still can't find it, it's the section with the bluish water-like light at the end), there should be a series of pipes wrapping around the bottom right hand corner of the tunnel. They are big enough to get your ship through, so go under them and keep going through them until you pick up the upgrage. This makes the targeting computer a little more precise, and it also makes it so you don't have to hold down the Y-button.

Note: It is best to do this with the X-Wing, andnot the Falcon, due to size constraints.

All Tech Upgrades:
First type in AYZB!RCL then type in WRKFORIT.

Art Gallery:
Type in EXHIBIT! at the passcode screen and you'll hear R2-D2 beeping. Go into the extra features menu and the art gallery will be unlocked.

Audio Commentary:
Enter the following code into the passcodes screen:
BLAHBLAH

Black and White Mode:
Enter LIONHEAD as a password

C-3PO, R2-D2, and their pod:
In Tatooine Traning, you can find either C-3PO, R2-D2, or the escape pod they crashed in as a bonus item. You will only be able to find one of them each time you do the traning, so you will have to look around.
C3PO = Blow up Jabba's Palace and look on the ground.
R2D2 = Blow up the sandcrawler and look on the ground.
POD = Out in the desert. Look around for it.

Cheat on the Beggar's Canyon race:
Trying to get the Naboo fighter? Well here's the easiest way to beat the Beggar's Canyon race. When Biggs goes down path 1 go down it until it says path 1. Now carefully slow down and go down and left, then as carefully as you can turn around and go to the start, then go down path 2. You'll still get credit for doing race 1, just remember to go back and do race 2.

Doing the turn around can take some practice but it's a lot easier than doing race 1. Also remember to stay low. If you scrape the wall a little bit it's okay, just don't scrape it too much.

Documentary:
The documentary option in the special features menu (which lets you see the making of the game) will only be unlocked after you beat all 10 normal missions of the game.

Free life/resupply:
When you get to a break in a mission, the split second before it is about to enter a cut-scene, crash/destroy your ship so that the cut-scene starts before the crash scene ends. When play resumes, your ship will be fully shielded, and you will not have lost a life in the process!

Get the Naboo Starfighter:
CDYXF!?Q, then ASEPONE!

Mission quick-start:
Hold down the L and R buttons all the way and select a mission. You should skip the available ship screen and the hangar and will automatically begin the mission in the Default Craft.

Music Hall:
Enter COMPOSER as a passcode. This will unlock a sound test-like area under Special Features.

Play as Naboo Fighter:
Beat the Tatooine Training Session at all 4 times-morning, afternoon, evening, and night. You have to complete all of the objectives, find all of the discovery items, and get the two hidden bonus items in each session.

Skip the Hangar:
Hold down both R and L buttons while selecting a mission to skip the Available Craft screen and the hangar. You will then play the mission in the default craft.

Slave One Color Change:
To get the slave one paintjob from episode two, type these codes in.
VV?GXRYP
CNOOQ!ZR
JFETTSHP
take note, it will NOT work if you already dont have the slave one.

Spread Proton Bombs:
In ''Imperial Academy Heist'' steal the shuttle and go in the tunnel to your right to grab the tech upgrade.

Targeting Computer Upgrade:
In the ''Attack the Core'' level, fly inside the Death Star until you are near the central core...a short way before the large opening, there are some pipes near the lower right. Fly under them to get the Targetting Computer upgrade.

Unlimited lives:
Enter JPVI?IJC as a password. R2D2 will not beep for this password. Return to the password screen and enter RSBFNRL as a second password. R2D2 will beep to confirm correct code entry.

Unlock ACE mode:
Type in U!?!VWZC And the wrong code sound should happen. Then type GIVEITUP To unlock ACE mode more easily than getting medals.
Magazine

Unlock All Original 10 Missions:
First enter !??QWTTJ (will get false beep), then type in Classic

Unlock audio commentary:
Get bronze medals on 10 main missions. Check the special features menu for the Audio Commentary.
Source: IGN

Unlock Bonus Mission Death Star Escape:
Enter in PYST?OOO. Without exiting, enter in DUCKSHOT. The mission will appear above Death Star Attack.

Unlock Credits:
Type in THATSME! as a passcode

Unlock Documentary:
Type in ?INSIDER as a passcode

Unlock Endurance:
Enter ?WCYBRTC Then enter ??MBC??? into the passcode section.

Unlock Imperial Shuttle:
First enter AJHH!?JY as a passcode then enter BUSTOUR

Unlock Millenium Falcon Code:
1st enter MVPQIU?A and then OH!BUDDY. Then you will unlock the Millenium Falcon without having to get 10 Bronze medals.

Unlock Revenge on Yavin Level:
Enter ''OGGRWPDG'' first. (even though you get the incorrect beep) Then enter ''EEKEEK!''.

Unlock shuttle in extra missions:
To unlock the shuttle in Triumph of the Empire and Revenge on Yavin, You must get a Gold medal on BOTH OF THEM.

Unlock Slave 1:
To unlock Slave 1, Boba Fett's ship, get 12 Silver Medals in all 10 primary missions, Death Star Escape, and The Asteroid Field.

Unlock Slave I:
Enter PZ?APBSY then IRONSHIP in the Passcodes. This will unlock the Slave 1.

Unlock the Astroid Field Bonus Level:
Type in TVLYBBXL then NOWAR!!!

Unlock the Car:
Enter the following code as a password
!ZUVIEL!
then enter
!BENZIN!

Unlock the TIE Fighter:
First enter ZT?!RGBA (will get false beep), then type in DISPSBLE

Unlock Tie X1:
Enter NYM!UUOK Then enter BLKHLMT! Into the passcode section.

Unlock Triumph of the Empire bonus level:
On the passcodes screen type ''AZTBOHII'' (will get an incorrect beep) then enter ''OUTCAST!'' without leaving. It will be above Strike at the Core on the stage select.