MacOS support via Mono was done early on, but was not tested or used much. Since 2015 our nightly builds also run Mac OSX platform conversion and check if everything works. So it works internally for us right now. Work continues here after the release of our first own product, which will also be released on MacOSX on Steam.

Since all source code for PC platforms is available (early 2014 release) and free to use, you can also try compiling directly on MacOSX (best to use OpenTK and fix any remaining linking issues with it) and your game should work just fine :) More advanced OSX features are coming in the future.