According to Nintendo, the company just keeps breaking its own records. Shortly after it revealed that the Switch and The Legend of Zelda: Breath of the Wild broke sales records for a new Nintendo console and launch title, respectively, the company announced that Mario Kart 8 Deluxe is its fastest-selling entry in Mario Kart history.
Mario Kart 8 Deluxe is an updated port of Mario Kart 8, which debuted on the Wii U in May 2014, for the Switch. This version of the game includes all of the original's downloadable content, adds three new characters, and expands the Battle Mode with additional maps and game types. It's essentially the definitive version of the Wii U's best-selling game on Nintendo's latest console--and the biggest Switch game to debut since Breath of the Wild.
Nintendo said more than 459,000 copies of Mario Kart 8 Deluxe were sold on its April 28 launch date. That compares well to Mario Kart 8's lifetime sales; the company said on its website that 8.31 million copies of the original game were sold between its May 2014 launch and December 31, 2016. The Wii U version also had a roughly 65% attach rate, and based on just one day of sales, Mario Kart 8 Deluxe's attach rate is already about 45%.
The company also claimed that Mario Kart 8 Deluxe has been well-received by critics. It said:
Mario Kart 8 Deluxe has also received more perfect review scores than any other Mario Kart game ever. With a current Metacritic score of 93, the critically acclaimed title is the highest-rated game in the series in 15 years – tying the overall review score of Mario Kart: Super Circuit for Game Boy Advance.
Nintendo has been oft criticized for "padding" the Switch's launch with ports of and sequels to Wii U games. Breath of the Wild started as a Wii U exclusive before heading to the Switch, Mario Kart 8 Deluxe is an enhanced version of Mario Kart 8, and Splatoon 2 is a follow-up to the company's third-person shooter. Why rush out to get a Switch when some of its best games are available on a console millions of people already own?
Yet these broken sales records and favorable critical receptions show that Switch owners don't mind these ports and sequels. Some of that is bound to come down to wanting something to play--the Switch doesn't have the vast library of the PlayStation 4, for example--but much of it could result from the Wii U's lack of popularity. The Wii U sold roughly 12.8 million units in its lifetime; the Switch sold around 2.7 million systems in one month.
So is there a good reason to upgrade from Wii U to Switch? That depends on your priorities, especially because the Switch is far more portable than the Wii U, but right now there aren't many games you can't play on the console you already own. That, however, doesn't matter to Nintendo. Most people don't own a Wii U, and if porting that console's best games to the Switch keeps leading to record sales, the company's probably going to keep doing it.