BlameThePixel!

Official website and download
http://kart.nexon.net/
(beware: in order to make changes to your account you MUST remember the answers to your secret questions)

Wiki info:
http://en.wikipedia.org/wiki/Kart_Rider

Basically this game has 2 mode:
- speed which is all about drifting
- item, which is all about attacking each other with items
Both can be played single and teamed, so it has 4 modes total.

Your rank advances when you get Racing points, see the wiki
Lucci-cash can be spent to buy items/characters/cars

- Theres an offline quest mode, it has newby quests for you to play. Basically this is about learning the game-menu. You earn lucci for completing quests
- Theres an offline story mode where you have to race tracks. You can earn items/cash/racing points here.

Youtube holds loads of movies. Some are korean, the game is called popcart over there and has many more features.

Cheers,
Djoszee

Looks a bit too wacky if you ask me! I don't really see the appeal.

It's Korean and associated with MapleShit.

...and im making some hacking progs for it.^^
EDIT: its not only korean.
NAKR = NorthAmerican KartRider
KKR = Korean KartRider
PR = Chinese KartRider (PopKart)