As long as you have at least one of the three versions (Windows, Linux or MacOS) you create the other two, since it's a Renpy-game it's very portable. It will take some work in the CLI though, so don't bother if you're not comfortable working with the Terminal.app.
This script handles almost everything for you:
You must be registered to see the links
It won't run on a Mac out of the box since you lack wget but that can easily be replaced with curl, or you could install wget I suppose.
I also had issues getting it to recognise what Renpy-version to use. Not sure if that's my own setup, but the version can be supplied manually at the end of the call. This game uses 7.1.3, which can be verified by looking at line 44 of: KirsESS005-1.0-pc/renpy/__init__.py
A simple port would be created by running:
Code:
./renpy2linux path/to/KirsESS005-1.0-pc 7.1.3
While it won't be packaged exactly like Renpy normally does with the game, lib and renpy-folder outside of the game.app, it still works just fine. If you want to tidy it up, you can rework the links inside the game.app and move the folders inside.