You must be on the menu screen that looks like you are on the bridge of the Excelsior to enter the following codes. If done correctly, a text response will appear in the top right corner of the menu.
At the bridge screen, press R1, L1, Circle, Square, L1, R1, Triangle, Select to unlock all levels.All ships
At the bridge screen, press L1, Square, L1, Square, R1(2), Circle, Select to unlock all ships.Invincibility
At the bridge screen, press L1, Circle, L1, R1, Triangle(2), Circle, Select.All medals and ranks
At the bridge screen, press L1, R1, L1, Circle, R1, Triangle, L1, Select to unlock all medals and ranks.Kobayashi Maru difficulty setting
At the bridge screen, press L1, Triangle, L1(2), Square, Triangle, R1, Select to unlock the Kobayashi Maru difficulty setting.
When you intercept a starship and are having trouble destroying it, fly up behind it. They all have phasers on the back, so pull up beside an engine. Concentrate your fire on that engine. If done correctly, you will not get hit while destroying the starship. Also when attacking an "Akula" class starship, disable its shields, then go directly in the middle to the impulse engines and fire at the ship. This works almost all of the time. The only thing that could hit you are the fighters.Attacking the Orions
When attacking the Orions, you do not have to destroy both Orion starships. Just disable the shields on each ship, and they should warp out of there.