You need more than one week to determine if a game is a major flop. This game barely had a week in the market so it's not right to call it a major flop.
Things like the PS4 in Japan are considered a major flop though as they had several weeks to sell and it couldn't beat the first weeks of the Wii U.
"I've Underestimated the Horse Power from Mario Kart 8, I'll Never Doubt the WiiU's Engine Again"