To unlock everything

Press L&R at the title screen. You'll hear a voice say "Ok, Good" When you begin a new game, you'll have access to all the stages and all the craft. Also, you'll have a score of 100 on every blue Impluse Mission.

Exhibition mode (Jap Version)

Successfully complete all twenty Blue Impulse Missions. Exhibition mode includes new manoeuvres which were previously unavailable.

Bonus mission

Successfully complete Sky Mission Attack 1 through 7. Then, Sky Mission Attack 8 will be unlocked.

Bonus options

Enter "TASCAS" as a name. Then, choose the "Special" selection on the options menu to access "HUD", "Cockpit", and "Player Assist" options.

Five or six jet formation

Successfully complete Sky Mission Attack 1 through 8. Then an option to fly a five or six jet formation in free flight mode will be unlocked.