I was wondering the same thing. Right now I know what platform I want it for, and I want to give it a try. So over to GOG I go (because steam and epic have Windows and Mac it looks like, and GOG has all three).
I'd much rather get it on itch, as it's the place I most want to get my games from. But it seems for some reason, bigger games just don't end up showing up on all platforms here. Even when they are available for all platforms.
Viewing post in Spiritfarer®: Farewell Edition comments
Mac has just been uploaded. Linux build will follow this week. Thanks for your patience!
Generally, from the devs perspective, it's the support of all builds across all systems that causes the delays here. Every build on every store needs to be adequately tested, one at a time, before we publish it; and we'll understandably prioritize the builds/stores that get the most users.
Meanwhile, since the GOG linux build is currently being patched, we're waiting 'til that's stable before adding it here.