Hi George,
nice to hear that it works good on Arch Linux. Yes, I use the Godot Engine (this is hopefully mentioned in the games credits). It has been an easy start with godot. A downside might be much less 3rd party assets & code. Although there is a very lively community.
Sometimes I create the assets myself, sometimes I use assets with a free license and sometimes I get permission by very nice people to use i.e. their photographs or 3d models. Although there remains often still much work to reduce the poly count, combine textures and so on. Any sources which are not cc0 are mentioned in the credits.
There might be a version with slightly higher fidelity available in the future for the Desktop platforms (Linux, Windows, Mac) which will either require Open GL3 (many low spec PC graphics support OpenGL3 but get much slower frame rates compared to OpenGL2) or Vulkan. Which might include better lighting/shadows, mirroring surfaces/water, better textures here and there as well as maybe some replaced 3d models for foliage. Probably such a version might be offered for a few pounds/euros via the
itch.io platform.
Cheers,
Michael