During the intro scenes (when you see the jets fly) enter the following code: Up, C-Down, left, C-Right, down, C-Up, right, C-left, L, R, Z. You should now hear a chime to tell you the code worked. Now select Main Game

Mission select

During the intro scenes (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 now hear a chime to tell you the code worked. Now select Main Game

Spanky

Find and complete all 3 bonus missions in the game and Spanky, a new pilot, will be enabled.

Mao Mao

On the title screen, press: C-Left, C-Down, C-Right, C-Up, C-Left, C-Right, C-Down for Mao Mao.

12 planes

For each normal mission you complete, a new plane will be added to the deathmatch plane select menu. If you have Mao Mao and Spanky, that will make 12 planes.

Ice Cave

There is a secret stage after you win the Ice Cave stage. It waits for a player who can complete all three bonus stages and all seven regular stages.

Third bonus stage

The third bonus stage is played after Fortress if you have already won the first two bonus stages.

Second bonus stage

To reach the second bonus stage you will need to complete Tokyo, Pacific Ocean, and Air Battle very quickly. If it's sunset when you reach the Desert stage you're already too late to save the shuttle.

First bonus

To reach the first bonus you must complete Tokyo and the Pacific Ocean stages with a very high score.

New F-15 plane with a girl pilot

On the title screen, (full screen logo, and "Press Start") C-Left, C-Down, C-Right, C-Up, C-Left, C-Right, C-Down. Don't be discouraged when you don't hear a sound or see something new, because nothing will happen. Go to any plane select screen, and on the far left, you will see a new F-15 plane with a girl pilot.

Alternate color

Press R at the plane select screen. (Only works in Main Game and Boss attack) To select the alternate color in Death Match, Hold the R button while selecting your plane. (Only works for the four original planes.)