DS had 2 million more hardware units sold than 3DS at the same time and NSMB DS was the first 2D Mario game in a long time, which is why people quickly flocked to it. Series fatigue people.
By the way, the game releases in 4 hours. Just wanted to point that out. ;)
Read my original story on Fictionpress (Shinigami Twin): http://www.fictionpress.com/s/2996503/1/Shinigami-Twin
As well as my other one (Hell's Punishment): http://www.fictionpress.com/s/3085054/1/Hell-s-Punishment
Nintendo Network ID: kingofe3