Mario Kart 3DS Cheats :
Code - How to unlock secret minigames!!!!
by Unregistered Apr 10, 2012
first you must get 3 stars in 50cc prix. sounds hard but its easy enough. select 100cc in the main menu. use metal mario and place 1st or 2nd in the first race. exit and delete your save. dont worry either because for some reason ( really dont know why) all your progress is still there, your new save will have secret minigames. get 2 3DS and you can play 2 player with them!
worked for me on my 3DS
hope this works guys!!!!