Super Mario 3D World was released in Japan last week and sold 99,588 copies in its first week—a rather low opening for a game that is expected to turn the Wii U’s fortunes around for the foreseeable future, and the worst opening of any Mario platformer in recent years.

Here’s something one should know about Mario games in general: 3D Mario games don’t sell as well as the 2D ones, especially in Japan. There are a number of theories as to why this could be, ranging from motion sickness to your average Japanese person being intimidated by large exploratory games. And so, ever since Super Mario Galaxy 2, Nintendo have been attempting to bridge the game between 2D and 3D Mario titles.

Super Mario 3D World is the latest platformer in the series to attempt this, and it builds upon the successful foundation established by Super Mario 3D Land on the Nintendo 3DS. And this is why it’s disappointing to see the game open with such low sales—because it was clearly meant to make more of an impact.

Japanese sales tracker Media Create reports that Super Mario 3D World sold through 57.17% of its shipment, which means that Nintendo only shipped around 175,000 copies of the game for its launch. That’s a rather low opening shipment for a Mario game, and it either means that Nintendo had realistic expectations or that retailers did, and weren’t wiling to accept any more copies of the game at launch. After all, shelf space is limited and valuable.

Additionally, while this holiday season will certainly provide a boost to Super Mario 3D World sales, one wonders how well the game will sell after the holiday period. After all, it’s consistent sales throughout the year that led to the success of games like Super Mario 3D Land.

Perhaps there’s just been too much Mario of late. We’ve seen four Mario platformers over the last three years alone. Super Mario 3D World is competing with three other Mario games—one of which is on the same platform. It should be interesting to see how its sales hold up over time.