Game was originally launched on kickstater as Windows and Mac supported. Got Linux support as kickstarter stretch goal in February 10, 2014

https://www.kickstarter.com/projects/rain-world/project-rain-world/posts/743743

On March 28, 2017 game was released to Windows and Playstation 4. A later version game was released for the Nintendo Switch in late 2018.

Last note on Mac/Linux release.
https://gtm.steamproxy.vip/app/312520/discussions/0/135511655653640988/#c135511757694791603

Zero updates from developers about Linux support since. Game uses Unity engine.