To change your character's outfit, press UP or DOWN on the character selection screen.
Increase speed by 30%:
Hold up anytime during straight sections.
Mogule Jump:
At a jump point, rotate d-button 360 degrees, then jump.
Acro-ski:
Tap down-up-action_button during any straight section.
1) Complete the game (arcade or saturn mode) with more than 10000 points;
2) Hold L+R before selecting any play mode and Jef will replace B.B.
During each event's title screen (ie. when the world record is shown), tap left-left-left-right-right-right.
Backwards somersaults:
Whilst you are setting the angle of jump (ie. whilst pressing B), tap down-up, then jump off at 60 degrees.
Increase distance:
Hack the run buttons whilst in flight to increase distance.
Mogule Jump:
Same as 'backwards somersaults', except tap left-right.
Super V Gliding:
Tap right-left BEFORE you set the angle of jump.