He started with Mario Kart last Christmas when we got the Wii (he turned 5 in September so he was 4 when we got it). He has finished in 1st place in all cups and races, as well as first in 2 mirror mode cups. I think that he as all but 3-4 of the charactes unlocked. He also plays Super Mario Galaxy 2 and he is on the 2nd or 3rd World. He doesn't like games if they're not Mario.