Simutrans, an open-source game similar to OpenTTD and TTD, has a Haiku port but the latest version of the port listed on the website is stuck on 112.2:
HaikuDepot has a version on 120.0 (last updated in 2019), and the latest version of the game is 122.0.
Just wondering if anyone on here is interested in taking up maintenance of the port since it looks like work on the Haiku version has become stagnant. FYI, Simutrans is hosted on Sourceforge, so you can access the source and upload completed files there.
For anyone who’s interested, I’d strongly recommend joining the official forums just to get some advice and tips on how to get going (and maybe ask them to update the Haiku listing whilst you’re there):