Great sales. When the 1 million milestone was announced, the steam version was at 575k. Taking this into account, the game has sold at least 1.425 million, and that if w10/Xbox sales completely halted.
Bet with Intrinsic:
The Switch will outsell 3DS (based on VGchartz numbers), according to me, while Intrinsic thinks the opposite will hold true. One month avatar control for the loser's avatar.