Level select

At the "Press Start" screen, press L1, R1, L2, R2, Triangle, X, Circle, Square(2), Circle, X, Triangle. Then, return to the "Start Mission" screen to select any level in the game.

All ships, weapons, and upgrades

At the "Press Start" screen, press L1, R1, L2, R2, Up, Down, Right, Left(2), Right, Down, Up.