This is the best Mario Kart yet to date. It has taken many of the great items, moves, and tracks from previous games and combines it with new items, moves, and tracks all on one tiny DS disk. I usually start with a bit of a critique, but this time I really don't have one. Perhaps my critique is that they didn't release a mirror of this game for the Gamecube. It will be intersting to see what they decide to do for the first Mariokart on the Wii.
There is an excellent variation between characters, and the fact that the WFC (internet) hook-up comes to you at no cost (presuming you have a wireless router) you can play with others all the time.