dude this game is the most amazing game on ds (besides advance wars i mean) the online play is intense and mostly sweet
User Rating: 9.8 | Mario Kart DS (DS Bundle) DS
the game has tons of missions and circuits to keep entertained for hours and hours. and even if it gets boring (highly unlikely) the online play will be the best mario kart experience of all. as a proud owner of all the mario kart instalments i am very familiar with the tracks karts weapons powerups and so forth. there are at least 30 new powerups in the game and all of my favorate tracks are here too. the new thing here is online play. going online is....well.....fun. connection to wi-fi takes a few seconds and setup is easier then pam anderson (lol). i even used the wifi setup to look for wifi for my laptop. the opponent matching is very well thought through keeping the opponents at or slightly higher then your level thus keeping the game play fast-paced and intense. the human players obviously make up for mediocre a.i. which seems to be the only flaw with this game
i recommend it to anyone and everyone with a ds 
