It was also on PC, 3DS, PS4, Vita and Xbox One
Speaking to Nintendo Everything, Inti Creates has confirmed that the game has sold “over 600,000 copies.” Studio CEO Takuya Aizu explains that the boost is “in part powered by the release of [the sequel].” Aizu also states that “more than half of those sales” are from the Switch edition. Quite the feat given that it was also released on every other major platform.
Note that Curse of the Moon came out in mid-2018, so it has some long legs if it’s just now reaching that milestone. While it was available on PC, 3DS, PS4, Vita and Xbox One in addition to the Switch, the sequel shored up some of those platforms, only appearing on PC, PS4, Xbox One and Switch.
It makes perfect sense that if there is more of a global saturation of Switch users in 2020, folks who picked up the second game on the platform would mosey on over to the original.
Bloodstained: Curse of the Moon 1 has sold over 600,000 copies, more than 50% on Switch [Nintendo Everything]