Mario Kart DS/Unlockables

Mario Kart DS can be enjoyed without learning the advanced maneuvers. You'll find lots of secret unlockables within the game.

Unlockable characters
A good, fast character with medium cars and lightweight movement with good agility and handling.
 * Metal Mario: Get a gold trophy (first place overall) on 50cc Retro Grand Prix Lightning Cup

Pathetic speed on all cars but good acceleration and traction with low, medium, and high item.
 * Dry Bones: Get a gold trophy (first place overall) on 50cc Nitro Grand Prix Special Cup

Bit over medium speed, low item, and medium for the rest.
 * Waluigi: Get a gold trophy (first place overall) on 100cc Retro Grand Prix Lightning Cup

Great cars with good acceleration with low, medium, and high item. Awesome speed and kinda heavy though bad drifting.
 * R.O.B.: Get a gold trophy (first place overall) on 150cc Mirror Nitro Grand Prix

Unlockable karts

 * Earn a third kart for each character by placing first overall in the 100cc Nitro Grand Prix
 * Earn four additional karts for each character by placing first overall in the 150cc Retro Grand Prix
 * Unlock all karts for all characters by placing first overall in the 150cc mirror Retro Grand Prix

Unlockable 150cc mirror mode
Unlock 150cc Mirror Mode by placing first overall in 150cc Retro and Nitro Grand Prix.

Unlockable title screen
You can unlock a new title screen by finishing all classes with gold trophies on all classes and classes and cups.

Unlockable ending screen
You can unlock a new ending screen (the 'thank you' screen) by earning gold trophies on all cups and classes.

Unlockable mission tier 7
You can unlock a 7th set of missions in 'Mission' mode by earning at least 1 star on every other mission available.

Stars
You can unlock having a star by your name in NWFC matches by completing all Grand Prix cups with 1 star or higher. the number of stars that appear by your name in NWFC matches will be determined by the lowest grade you have on any race in Grand Prix mode. For example: If you have 1 star in any Grand Prix cup, but you have 2 stars or higher on all the other cups, one star will still be displayed by your name. If that one star gets pushed up to 2 stars, 2 stars will then appear by your name in all NWFC matches. Although extremely difficult, it is possible to have 3 stars by your name by achieving a 3 star rank on all Grand Prix cups. It is possible albeit very rare.