Seems that Stardeus is not the only RimWorld inspired space colony sim around, with Nebula being another that plans to release in 2023. It recently finished crowdfunding on Kickstarter, with $87,290 from backers. You can support it still via their SlackerBacker.
In Nebula you build up your starship, and then guide it through space and explore "millions" of star systems and planets that feature "diverse factions and unique environments". So it's basically a blending of RimWorld and Stardeus together. See the trailer below:
Certainly sounds and looks good, although it is very ambitious. With space and planet exploration, along with your colonists each having simulated physical and personality traits there's a lot going on. The quest system sounds like a lot of fun too having you do all sorts of things including retrieving valuable artifacts and defending locals from invasions.
Thanks to the amount of funding they gathered a few extras will be added in like animal taming, a full soundtrack, Z-Levels (underground exploration), moons, vehicles and more. Seems like it's worth keeping an eye on.
In the Kickstarter FAQ, they confirmed their plans for other platforms:
After the Early Access phase, we are also planning to bring Nebula to the Mac and Linux platforms.
Follow it on Steam.