Although it's only been on release for a grand total of six days, Super Mario Odyssey has managed to shift over two million units in Europe in less than three days.
The game is now officially the Nintendo Switch's fastest-selling game in Europe, and is now also the fastest-selling game in the Super Mario franchise in Europe - beating Super Mario Galaxy 2's previous record. On top of all these accolades, the game now joins Legend of Zelda: Breath Of The Wild as one of best-reviewed games ever made. The game currently has a 97% score on Metacritic based on 85 reviews, with 43 of those reviews giving a perfect score.
So, yeah, it's no wonder this game is selling stupidly fast when it's got this kind of critical acclaim.