At the title screen where it says "Press Start," punch in the following button combination: C-Left, C-Down, C-Right, C-Up, C-Left, C-Right, C-Down. You will now be able to fly a new F-15 plane, complete with a new pilot.
When you see the jets fly enter the following code: Up(D-Pad), C-Down, Left, C-right, Down, C-Up, Right, C-Left, L, R, Z. You should hear a chime to tell you that the code worked. Now select Main game and pick the mission you want--from Tokyo to Space.