All Cars, Tracks and Difficulties  -  At the Mode Select screen, press L, Z, R, C-UP, C-DOWN, C-LEFT, C-RIGHT, START. You should hear a chime if you did it correctly. 

Change Car Colors  -  To change your car's colors, simply press the R-Button during the car customization screen. Note that there are only a few select colors for each vehicle. 

End Credits and Final Six cars  -  Beat the Jack, Queen, King and Joker Cup on Novice, Standard and Expert difficulty to see the game's end credits. After resetting the machine, the title screen and intro music will change and the final row of six cars will be selectable. 

Fall through track in Port Town  -  To fall to in Port Town first you have to be on the second lap then right before the first speed boost use the booster. In the air turn until you see two signs, then land. 

Ghost Times  -  If you beat a certain time in the Time Attact Mode, you will unlock a ghost which is hard to beat (harder than the Master Mode.) Here are the times: 

Mute City 1:23:000
Silence 1:13:000
Sand Ocean 1:15:550
Devil's Forest 1:23:000
Big Blue 1:35:000
Port Town 1:36:000
Sector A 1:22:000
Red Canyon 1:19:000
Devil's Forest 2 1:24:200
Mute City 2 1:19:000
Big Blue 2 1:07:000
White Land 1:40:000
Fire Field 1:23:000
Silence 2 1:35:000
Sector B 1:45:000
Red Canyon 2 1:40:000
White Land 2 1:13:000
Mute City 3 1:46:000
Rainbow Road 2:11:000
Devil's Forest 3 1:20:000
Space Plant 2:04:000
Sand Ocean 1:35:000
Port Town 2 1:52:700
Big Hand 2:27:000

Joker Cup  -  To get the Joker Cup and six additional tracks beat the Jack, Queen, and King Cup on Standard difficulty. 

Master Difficulty Level  -  If you beat the Jack, Queen, King, and Joker cup you'll get extremely hard Master Difficulty. 

Mute City II Shortcut  -  Right after you make the third hard turn, you will see a ramp to the left that looks like it will lead you off track. If you hit it with a booster, you will fly over the gap and onto the next strip of tracks. 

Rainbow Road Shortcut  -  At the top of the first big drop, drive off the side of the track and tilt backward. Starting from 30th, this will put you anywhere from 20th to 1st, depending on how well you pull it off. 

Rotate Cars on Customization Screen  -  Want to see your car from different angles? At the customization screen press the C-Buttons to rotate the car in all directions. 

Rotate Track on Selection Screen  -  Want to see the track from different angles? At the track selection screen press the C-Buttons to rotate the track in all directions. 

Sector B Shortcut  -  Towards the end of the Sector B track, as you are going up the hill, turn LEFT after the wall disappears. Immediately push the control stick UP so that your ship lands on the other section of track.
Note: The shortcut will not allow you to refill your energy meter in the pit area. 

Smaller Cars  -  At the car select screen press and hold the L and R buttons. While holding those buttons, press C-LEFT and C-DOWN to shrink the cars. 

Spin Attack  -  To use the spin attack just hold the Z bottom and tap R twice or just do the reverse. (This method is very useful in "Death Match" if you time it just right). 

Title Screen Changes  -  To have the title screen change to a comic book motif, beat F-Zero X on Expert. For a second change, beat the game on Master difficulty. 

X-Cup Track Generator  -  Beat all four cups on Expert difficulty to open F-Zero's hidden X-Cup. This cup will randomly generate six courses, ranging from utterly boring to plain cool. Beating the four cups will also open a Master Difficulty level.