Cheat mode:
Press Start to pause game play, then press Left Analog-stick Up(2), Left Analog-stick Down(2), Right Analog-stick Left, Right Analog-stick Right, Right Analog-stick Left, Right Analog-stick Right, L3, R3. A sound will confirm correct code entry. Damage will be repaired and you will have full missiles. Note: This code can only be enabled one time per mission.

Play as Ellen McNichol:
Focus the game play with Ken. Every time you see Albert, shoot him down. Try shooting him down in every mission. If done correctly, Ellen will be unlocked for the space missions. Ellen has planes such as the Bird Of Prey. You must shoot Ellen and Albert down in the missions The Gale, Doll Master, Navarone Campaign (Wind Valley), Operation Skyscraper, and Meteor Structure. You do not need to play the entire game as Ken -- only the missions that were listed. Also, doing stand by missions is not recommended.

Bonus planes:
Successfully complete the game and save when prompted. Use that saved game to continue a new game. Successfully complete the Blue Wing Knights mission, then choose another mission. Press Square at the aircraft selection screen to choose from the Vic-Viper and other bonus planes. The Vic Viper has a longer range machine gun that can destroy an enemy plane with one hit. Other bonus planes such as the TwinBee, MX5000, Falsion, Blue Thunder M-450, Manbou-J, Flint-Rock, Aura-Wing, Jerry Mouse, Block Shooter, Super Fighter, Penta, Axelay, and Poly will also be unlocked, depending on how well you performed in your cleared saved game. You can clear the game on the same file repeatedly to unlock more planes.

• Aura Wing: Buy 50% of all aircraft for all pilots.
  Axelay: Buy all aircraft for all pilots.
  Block Shooter: Earn all eight medals for a pilot.
  Blue Thunder: Buy aircraft for a pilot.
  Falsion: Destroy 150 aircraft with any pilots.
  FlintRock: Get 100 Ace Kills for a pilot.
  Jerry Mouse: Complete the game with a 1st Element pilot.
  Manbou: Complete the game with a 3rd Element pilot.
  MX5000: Destroy 150 ground targets with a pilot.
  Penta: View all the ending sequences.
  POLY: Purchase all aircraft for Ruth Valentine.
  Super Fighter: Get 150 takeoffs for a pilot.
  TwinBee: Complete the game with 2nd Element pilot.
  Vic Viper: Successfully complete the game, then finish the first
  mission in your nest game.

Completion bonuses:
Successfully complete the game, then start another game with your file to begin with all airplanes (including bonus planes), medals, money, stats, FMV sequences, and replay levels that were previously unlocked. You can also view all the characters in a gallery.

Hint: Easy money:
To earn double money, kill enemies using the machine gun (not missiles or bombs). You can use those weapons to damage enemies, but the last hit must be delivered by the machine gun. Some air enemies will give more than double the money. When you finish the mission you will see the scoreboard, showing the enemies you killed with the machine gun with double of the money than normally awarded.

Hint: Skull Medal:
Get shot down over thirty times.

Hint: Gradius reference:
Play an Earth mission with the Vic Viper to hear music from level 4 of Gradius. Play a Space mission with the Vic Viper to hear music from.

Hint: Self-destruct in the Vic Viper:
While flying the Vic Viper, pause game play then press Up(2), Down(2), Left, Right, Left, Right, X, Circle. The Vic Viper will self-destruct when the game is resumed.