At the end of the day, if you're running into this situation often, you're right VM would probably be the simplest solution - parallels or crossover are trusted options for that. If a mac user wants to play something more demanding like an unreal game that was not ported for mac, and their hardware is good enough to handle the game, setting up a windows partition with bootcamp will provide a flawless experience.
Whichever way they want to go, there are options.
And in this case I don't think it was the dev being too lazy to make a mac port, as this dev offers mac and linux as well as windows, so it's more likely that whoever is sharing the game here isn't bothering to share or create links for the other oses, don't know. I have ren'py set to port out for windows, linux, and mac, don't think I even need to reselect those options, so I just click a button to compile and it's done automatically for all three. Any dev who isn't porting their ren'py games to windows, mac, and linux either does not care about the other oses, or they really are the laziest devs in the world. Of course, I'm using a mac, so maybe if you develop on windows there's some crazy extra stuff you need to do to port out to mac, but I doubt it, since most devs here use windows and do provide mac versions. One issue I had early on was setting things up for android ports (think there were specials sdks I needed or something), and after going through the hassle to install what I needed, it did not work, and so I haven't bothered to mess with it since then (at some point in the future I'll look at again). However, someone else here made an android port, so that has been covered as an unofficial option.