F-Zero X 

All tracks, ships, and difficulty levels 
At the mode selection screen:
press L, Z, R, C-Up, C-Down, C-Left, C-Right, Start.
If you entered the code correctly, you will hear the sound of a chime.

Smaller racers 
At the ship selection screen:
hold L + R + C-Up + C-Down + C-Left + C-Right.

Larger racers 
At the ship selection screen:
hold L + R + Z + C-Up + C-Down + C-Left + C-Right.

Alternate colors 
At the statistics screen:
select a ship and then press R or Z.

Spinning ship 
During a race:
press Z + R to spin your ship.
This causes other ships to explode when they collide with your ship.
This technique is especially useful in battle mode.

Ship preview 
At the customization screen:
select a ship and then press C-Up, C-Down, C-Left, or C-Right to view your ship from various positions.

Track preview 
At the track selection screen:
press C-Up, C-Down, C-Left, or C-Right.

Alternate title screen 
Beat the game on the expert difficulty level to view the title screen in comic 
book-style. Beat the game on the master difficulty level to change the title 
screen again.

View lead time 
During a GP race:
press L to view the time between the your racer and the lead (if not already in first place)
or between your racer and the closest competitor (if already in first place)

Joker Cup tracks 
Win the Jack, Queen and King Cups on the "Standard" difficulty level. Then, a Joker Cup,
with six bonus tracks, will be available for game play.

X-Cup tracks 
Win the Jack, Queen, King, and Joker Cups on the "Expert" difficulty level.
The X-Cup is a group of six tracks that are randomly generated.

Master difficulty level 
Win the Jack, Queen, King, and Joker Cups on all three difficulty levels.