Mario has arrived on Switch, and business is good. Nintendo announced today that it has sold 1.1 million copies of Super Mario Odyssey in the United States. Reaching that sales figure after launching October 27, less than a week ago, makes Odyssey the fastest-selling Mario games in the history of the series, according to Nintendo. The excellent platforming adventure is also selling faster than any Switch release so far, including The Legend of Zelda: Breath of the Wild.

Nintendo separately announced on Tuesday that it has sold 2 million copies of Super Mario Odyssey worldwide in just thre days. In Japan, the game has also nearly outsold The Legend of Zelda: Breath of the Wild at physical retailers in less than a week.

“The public continues to respond positively to Mario’s latest adventure,” Nintendo of America boss Reggie Fils-Aime said. “We’re also seeing sales momentum for Nintendo Switch thanks to an ever-growing catalog of games from large publishers and indie developers.”

The success of Odyssey is a huge and important indicator for the state of Nintendo. It signifies that the Switch is healthy and still creating demand for content now that the gift-giving holidays are upon us. It also suggests that the Switch has a large audience of gamers that lean more hardcore than the audience that made the Wii a similar megahit. The previous fastest-selling Mario release was New Super Mario Bros. Wii, which is a simpler 2D sidescrolling platformer. Traditionally, 2D Mario games have sold better than 3D Marios because the former is easier for a broader audience. But eight years since the release of that game, the Switch has a huge player base that is hungry for the more complex Super Mario Odyssey.

And the reason that is important is because the more casual Wii audience didn’t spend a lot of money on additional software. But the game-to-hardware attach rate on Switch should end up a lot higher if it’s selling to people who buy and play a lot of games every year.