New Super Mario Bros
New Super Luigi U
Nintendoland
Kirby and the Rainbow Course
Yoshis Woolly World
Wind Waker HD
Mario Party 10
Mario Tennis Ultra Smash
Animal Crossing board game
Captain Toad
Splatoon
Super Mario Maker
I don't see any of these games having the need for sales numbers that big. Some still may have already passed that, others haven't. But regardless, look at each of these games individually. Most of them are not that resource heavy. 2m sales would mean that these games had a budget of at least 40m $ each (if we keep it real low and say the average revenue is 20$ a copy).