itch.io

Most probably they are using the same libraries they used for Linux, so it depends on what controller you have. I didn't manage to make mine work in Linux, but it worked out on Windows by launching it from Steam, so my suggestion is to try to add it as a non-Steam game on Steam on your Mac. If it doesn't work still try to tinker a bit with the controller settings in Steam's overlay, it might help!

Isn't the Linux version using SDL2 too?

My Steam controller does work fine on the openGL version in Win when I added the game to my Steam library. Too bad didn't managed to make it work on Linux. Still thanks! Got the bundle just for this game, thank you for supporting the cause!

Following. I have tried yesterday with a Steam Controller on Linux, and had no luck even configuring it to the in game keyboard keys.

I will have a look at the code when I have some time and let you know if I figure something out that helps us both!