Cheats:
All campaign missions and planes
Hold L2 + R2 at the main menu then press Square, L1, R1, Triangle(twice), R1, L1, Square.
Vampire MK1
Unlock the Vampire during game play. Then, hold L2 + R2 and press L1(twice), Triangle(twice), Square, L1 at the main menu.
Invincibility
Press Start during gameplay, then hold L2 and quickly press Square, Triangle(twice), Square. Release L2, then hold R2 and quickly press Triangle, Square(twice), Triangle. Release R2. Repeat the sequence to disable the code.
Increased damage by weapons
Press Start during gameplay, then hold L2 and quickly press L1(twice), R1. Release L2, then hold R2 and quickly press R1(twice), L1. Release R2. Repeat the sequence to disable the code.