https://www.pcgamer.com/shovel-knight-has-sold-2-million-copies-most-sales-on-pc-but-most-revenue-on-switch/

Retro platformer Shovel Knight, originally released in June 2014, recently passed two million copies sold. Developer Yacht Club Games dropped the number in a blog post, which also offers a detailed breakdown of where those sales came from. Before that, some more good news: in celebration of this milestone, Shovel Knight is 20 percent off on Steam, GOG and Humble for the next week. 

Shovel Knight originally released on PC, Nintendo 3DS and Wii U, so it's no surprise it's sold the most units on PC (24.4 percent of sales) and 3DS (23.9 percent of sales). More surprising is the Nintendo Switch's spot at third place (17.6 percent of sales) given its newness—Shovel Knight only came to Switch in March 2017.