All Cup Tour:
Win the Special Cup in the 150cc class to unlock the All Cup Tour, which is a
combination of all of the four default cups.
Special Cup:
Win the Star Cup in the 100cc class to unlock the Special Cup for all classes
in versus and time trial modes.
Mirror mode:
Win the All Cup Tour in the 150cc class.
Luigi's Mansion battle arena:
Win the Mushroom Cup in the 150cc class.
Tilt-A-Kart battle arena:
Win the Flower Cup in mirror mode.
Baby Luigi's Kart:
Win the Mushroom Cup in the 100cc class to unlock Baby Luigi's Rattle Buggy
Kart.
Birdo's Kart:
Win the Flower Cup in the 150cc class to unlock Birdo's Turbo Birdo Kart.
Bowser Jr.'s Kart:
Win the Special Cup in the 50cc class to unlock Bowser's Bullet Blaster Kart.
Daisy's Kart:
Win the Flower Cup in the 50cc class to unlock Daisy's Bloom Coach Kart.
Diddy Kong's Kart:
Win the Star Cup in the 150cc class to unlock Diddy Kong's Barrel Train
Kart.
King Boo's Kart:
Win the Special Cup in mirror mode to unlock King Boo's Pipes Kart.
Koopa's Kart:
Win the Star Cup in the 50cc class to unlock Koopa's Parakoopa's Para Wing
Kart.
Luigi's Kart:
Win the Mushroom Cup in the 50cc class to unlock Luigi's Green Fire Kart.
Petey Piranha's Kart:
Win the Star Cup in mirror mode to unlock Petey Piranha's Piranha Pipes Kart.
Toadette's Kart:
Win the Mushroom Cup in mirror mode.
Toad's Kart:
Win the Special Cup in the 100cc class to unlock extra characters Toad,
Toadette and extra vehicle Toad Kart.
Toadsworth's Kart:
Win the All Cup Tour in mirror mode.
Waluigi's Kart:
Win the Flower Cup in the 100cc class to unlock Waluigi's Racer Kart.
Parade Kart:
Win the All Cup Tour trophy in the mirror mode to unlock the Parade Car. This
is the car that you ride in if you finish first in any cup, at any class. Its
stats are: Speed 4, Acceleration 3, and Weight 4.
Alternate opening and ending screens:
Win the All Cup Tour in mirror mode.
All bonuses:
Win all cups with a "Gold" rank under all difficulty settings.
Taunts:
To taunt enemy racers, press X or Y without having an item.
Alternate title screen:
Hold X or Y at the opening screen when "Nintendo!" is spoken. Lakitu will then
appear with a fish on his rod.
Win a gold trophy to unlock an alternate title screen with all the characters.
Sites: