All planes and more
When the game loads and at the main start window where it says "PRESS START", push both the L and R buttons on the control pad. The announcer will say "GOOD OK" (or something to that effect), and you will have all planes, the dolphin, and the R/C car, plus all levels to fly in, including exibition mode.
Diffent views
Different views work differently for different kinds of tricks. Experiment during the tricks to see which one works best.
Exhibition mode
Successfully complete all twenty Blue Impulse Missions. Then "Exhibition" mode, which includes new maneuvers which were previously unavailable will be unlocked.
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.
Fly a car
Successfully complete Sky Mission Attack 1 through 8 with the Dolphin.
Fly a dolphin
Successfully complete Sky Mission Attack 8 to unlock a dolphin that can be flown in free-flight and sky mission attack modes.
Full pause screen
Pause the game and press X + Y.