Super Mario Kart

Mini Racer:
On the player selection screen highlight a character and hold Y and press A
Or press Y & A. Repeat to Un-shrink.

150cc Karts:
Win Gold in all 100cc Cups including the special Cup and a new 150cc Class will appear on the Class selection screen.

Race Your Ghost:
Complete a Time Trial in 1st Place then select retry to race yourself.

Race A Ghost CPU:
Select a 1 Player time trial. Press Start on Controller 2 at the player selection screen. The word COM will appear, use controller 2 to select a computer player to race against.

Extra Lives:
Win three races in a row.

Rear View Mirror:
Press X during a 1 Player game.

Rotate Replay:
Complete a Time trial without hitting anything of falling off the track, After race select the replay option pressing LB and RB will rotate screen.

Map On Top:
With a controller plugged into port 2, highlight time trial, hold LB & RB and press ST, ST, ST, select you driver and track. The map will now be at the top of the screen, and you will race in the lower half.

Reset Race Times:
In time trial mode select a track, now hold LB & RB and press Y, & A. Conformation dialogue will appear asking Yes or No.

Reset The Game Pak:
Hold LB & RB and press Y, & A. at the Title screen to delete all data. Conformation dialogue will appear asking Yes or No.

Switch screens:
Begin a One Player Grand Prix race and press B on controller two. Select a One Player game with controller two. Hold L + R and press Start on controller two. Select the class, driver, and track with controller two and begin game play.

Drive in the dark:
Begin game play in Battle Mode. When a player has one balloon remaining, hold B until losing a life. The player may continue to race in the dark.

Disable music:
Rapidly tap Start until the music ends. The game will continue with only sound effects until a star is used.

Special cup tracks:
Select Time Trial mode, choose a racer, and press Left to highlight the Mushroom Cup. Press L, R, L(2), R(2), A. A Special cup option will appear under the Star cup.

Turbo start:
Hold B just as the Lakitu's first light flashes.