Steampunk colony sim Steel Artery is here, and it's "emergent chaos" aboard a giant train

Steelpolis is more than just a train – it’s the last hope of a crumbling empire, and you’re in charge. I’ve been waiting for Steel Artery ever since it first popped onto my radar back in 2025, and it’s finally pulled into the station. The self-branded ‘train city builder’ bears closest resemblance to the likes of colony sims in the vein of Rimworld and Oxygen Not Included. The big difference is that you’re on a moving train. Boasting gorgeous pixel artwork and the need to exert careful influence on an autonomous, self-satisfying population, it’s a rich simulation that will look different with every playthrough.

“This is the message I’ve been waiting a long time to write,” developer ‘SoulAge23’ writes. “Steel Artery is now available on Steam. What started as an idea for a moving city builder eventually became Steelpolis: a living train-city filled with autonomous citizens, production chains, logistical headaches, social tension, and the kind of emergent chaos that only happens when thousands of independent agents are all trying to live their own lives at once.”

It’s your job to ensure that your mobile city operates smoothly, maintaining the well-being of all those hundreds or thousands of inhabitants within. Exactly how you choose to go about that is up to you – perhaps you’ll run a tight, efficient ship focused on supporting just one species, or maybe you’ll attempt to build a vast and culturally diverse megacomplex. Steel Artery is a flexible and complex simulation, so those who enjoy Rimworld and Dwarf Fortress will feel right at home, but others might be a little intimidated by everything going on at first.

With fully autonomous citizens that are motivated primarily by their own needs and desires, you’ll have to create opportunities and openings to get them to do what you want. It’s a tough balance to strike, however – you might bump up the financial incentives to entice workers into more lengthy, complex jobs, only to find that they’re retiring early with their earnings. At least they should continue to spend money and help keep your economy churning.

Each of the races bring their own culture, needs, and strengths to bear, so intermingling them can lead to a more productive society, but only if you can overcome any potential tensions between them. As your city chugs across the land, you’ll be able to stop in resource-rich regions to stock up on important supplies, but will need to factor in the space you have available. The whole train comes together with Steel Artery’s strong pixel-art visuals, ensuring you can see exactly what’s happening across the carriages at a glance.

Early Steam reviews are 89% positive, with the primary complaints being struggles with learning its systems and calls for more detailed tutorials. “Not a casual game,” one user writes, “this is the kind of management sim where one bad decision quietly turns into twelve new problems an hour later. I mean that as praise.” If you’re the sort of person who loves meticulously building a settlement in Dwarf Fortress, only to watch in a mix of horror and humor as it goes catastrophically awry, you’ll feel right at home. I certainly do.

Steel Artery is out now on Steam, with a 10% launch discount through Friday May 22. Expect to pay just $13.49 / £11.24 if you buy it while the sale lasts, or $14.99 / £12.49 afterwards. Head here to start your journey.

“For those of you who have followed development, shared feedback, wishlisted the game, or simply kept an eye on this strange train project over the years, thank you,” SoulAge23 concludes. “Reaching launch is something I couldn’t have done without that support. For those just discovering Steel Artery today, welcome aboard.”