Advanced shields:
Enter DROIDEKA as a code at the options menu. A sound will confirm correct code entry. Alternately, in level 1 when your friend's seedster has stopped, there should be an ATT shooting at him. Destroy the ATT and the power up is behind it.
Information in this section was contributed by Luis, Dravencorw, BOMBULL, BanthaThug, jlabdavis1403, and Ron Morris.

Advanced blasters:
Enter ADEGAN as a code at the options menu. Alternately, this can be unlocked in the "Liberation Of Camp 4" level. At the last shield generator, face towards the down-slope and there will be another up slope leading towards the upgrade.
Information in this section was contributed by Justin Lenssen and BOMBULL.

Rapid fire blasters:
Enter OVERLOAD as a code at the options menu. A sound will confirm correct code entry. Alternately, this can be unlocked near the end of "Sancuatary" level. There is a small valley to the right of the main valley. Inside is a volcano and a strange "fairy" object. The upgrade is behind it.
Information in this section was contributed by gjgg23230, BOMBULL, and Matt Rieckman.

Advanced bombs:
Enter BOOM!? as a code at the options menu. A sound will confirm correct code entry. Alternately, this can be unlocked in the "Glacial Grave" level, on the opposite branch of the river that leads to the gunboat hanger.
Information in this section was contributed by Dave and BOMBULL.

Advanced missiles:
Enter ?NUNAPWR as a code at the options menu. A sound will confirm correct code entry. Alternately, this can be unlocked at the beginning of the "The Smugglers Alliance" level. Help the civilians, even though the captain tells you not to. A speeder will come out of a homestead. Protect it and it will lead you to a farm with the upgrade.
Information in this section was contributed by Dave and BOMBULL.

Homing cluster missiles:
Enter &OVRKILL as a code at the options menu. A sound will confirm correct code entry.

Homing torpedoes and missiles:
Enter CANTMISS as a code at the options menu. A sound will confirm correct code entry. Alternately, this can be unlocked in the "Borvo the Hutt" level. Go northwest of the first battle to find a village among the trees and the upgrade.
Information in this section was contributed by Dave and BOMBULL.

Double secondary weapons:
Enter LCK&LOAD as a code at the options menu. A sound will confirm correct code entry.

Unlimited lives:
Enter PATHETIC as a code at the options menu. A sound will confirm correct code entry. Note: The game still counts how many times you died.
Information in this section was contributed by gjgg23230, BOMBULL, and Matt Rieckman.

One hit kills:
Enter EWERDEAD as a code at the options menu. A sound will confirm correct code entry. Note: This affects both the player and enemies. Note: Do not play a level were you have to protect something when this code is activated. Only use the code on levels 6, 7, 11, 15, as well as bonus levels 1, 2, and 3.
Information in this section was contributed by gjgg23230, BOMBULL, Ron Morris, and Matt Rieckman.

Bonus level 1:
Enter BYENABOO as a code at the options menu. A sound will confirm correct code entry.

Bonus level 2:
Enter LEC&FIVE as a code at the options menu. A sound will confirm correct code entry.

Bonus level 3:
Enter BADTEMPR as a code at the options menu. A sound will confirm correct code entry.

Expert mode:
Enter NASTYMDE as a code at the options menu. A sound will confirm correct code entry.

All ships:
Enter WAKAWAH! as a code at the options menu. A sound will confirm correct code entry. Note: This does not give you the bonus craft. This code has the same effect as you would get if you completed level 15 (Battle For Naboo).
Information in this section was contributed by Matt Rieckman.

Swamp Speeder:
Enter RHUBARB! as a code at the options menu. A sound will confirm correct code entry. Alternately, get platinum medals for all missions. The Swamp Speeder is a fast Republican ship and looks like a flash speeder in boat version. It moves very fast and it can shoot two lasers simultaneously at an extremely fast rate. Its secondary weapon is a heavy laser, just like the Gian Speeder. The Swamp Speeder is available on Naboo Bayou, The Andrever River, and Sanctuary levels.
Information in this section was contributed by Naboo_92289 and Matt Rieckman.

AAT:
Enter &&A!AT as a code at the options menu. A sound will confirm correct code entry. The AAT is the Trade Federation battle droid tank. The AAT is fairly slow and shoots two lasers simultaneously a medium-slow rate. Its secondary weapon are projectile bombs.
Information in this section was contributed by Naboo_92289.

Sith Infiltrator:
Enter SIENAR&! as a code at the options menu. A sound will confirm correct code entry. Alternately, you can play as the Sith Infiltrator once you access the third secret level, "The Dark Side". You can use the Sith Infiltrator in levels where you can use the Naboo Starfighter.
Information in this section was contributed by BOMBULL.

To get Homing Missiles for the Sith Infiltrator, enter CANTMISS as a code after it is unlocked. Play a level and ignore when the game states that you only have Advanced Missiles. Note: If you used the SIENAR&! code to get the Sith Infiltrator, you will have to repeat this after you restart your system.
Information in this section was contributed by Matt Rieckman.

Pink spaceship:
Enter RUAGIRL? as a code at the options menu. A sound will confirm correct code entry.

Car:
Enter EOCOAROS as a code at the options menu. A sound will confirm correct code entry. The Gian Speeder will be replaced by a 1969 Buick convertible.
Information in this section was contributed by Matt Rieckman.

View development team:
Enter LOVEHUTT as a code at the options menu. A sound will confirm correct code entry.
Information in this section was contributed by BOMBULL.

Developer commentary:
Enter TALKTOME as a code at the options menu. A sound will confirm correct code entry. Developer commentary, lasting about three minutes, can be heard in each level.
Information in this section was contributed by BOMBULL and Ron Morris.

View credits:
Enter MEMEME! as a code at the options menu. A sound will confirm correct code entry.
Information in this section was contributed by Justin Lenssen.

Unlock showroom art:
Enter KOOLSTUF as a code at the options menu. A sound will confirm correct code entry. Note: The music is not unlocked with this code.
Information in this section was contributed by BOMBULL and Ron Morris.

Concert hall:
Enter WAKEUP as a code at the options menu. A sound will confirm correct code entry.
Information in this section was contributed by BOMBULL.

Crazy camera:
Enter DRJEKYLL as a code at the options menu. A sound will confirm correct code entry. Note: This may cause the game to freeze.
Information in this section was contributed by Matt Rieckman and Justin Lenssen.

Droid driver:
Enable the EOCOAROS code, then play a level with the Gian Speeder. A Battle Droid will actually be piloting your speeder.
Information in this section was contributed by Matt Rieckman.

Homing Missiles for Flash Speeder:
Enable the WAKAWAH!, RHUBARB!, &&A!AT, SIENAR&!, all upgrade codes, LCK&LOAD, and EOCOAROS codes. Your Flash Speeder should now have seeker missiles. Note: The missiles may not always hit their target, and you will have to repeat this trick. It is important to follow that order and you need to enter all upgrade codes for it work.
Information in this section was contributed by Matt Rieckman.

Cluster Seeker missiles:
In the second secret stage, turn right immediately after starting to find a brown striped building. Enter the hole in front of it and turn left immediately before the path turns to the right. You will see it to your left.
Information in this section was contributed by Charles Reyes.

Federation Secrets secret level:
Successfully complete the standard levels with all bronze medals.

Coruscant Encounter secret level:
Successfully complete the standard levels with all silver medals.

Dark Side secret level:
Successfully complete the standard levels with all gold medals.

Hint: Queen's Gambit:
Get the homing cluster torpedoes. When you are in the hanger, take the Naboo Starfighter. Fly to the convoy and fire two cluster torpedoes. Start shooting at the convoy with lasers, then torpedoes. Continue to alternate. When reach the canyon, shoot at the pillars with your lasers to slow them down. If you still have some torpedoes, shoot them all at the convoy and finish the others with lasers.
Information in this section was contributed by Greg Andres.

Hint: Platinum medals:
It is also possible to earn a platinum medal by completing a level, including the secret levels, very successfully.