Unlock ALL Missions:
At the mission select screen press Up, Down, Down, Right, Left, Down, Up, Triangle.

Unlock ALL Jets:
Press Left, Left, Right, Down, Up, Down, Right at the 'Plane' selection screen.

Unlock Extra Time:
When the game is loading hold L1 + L2 + R1 + R2 + X + Circle + Square + Left.

Unlock Air-to-Air Missile Invincibility:
Choose your Plane and Weapons before the mission and When the 'Now Loading' screen appears hold L1 + L2 + R1 + R2 and rotate the D-pad counter clockwise.