itch.io

arguably true in the wider sense. Windows dominates, but I think you'll find a lot of coders prefer *nix distros like MacOS.  Mac has about 20% of the market now, and I bet the profile of that 20% could be closer to indie game markets than the broader market of just everyone, grandmas included. 

I agree with Daniel. not sure I'd promise extensive testing but you'll find out more than you know now by giving it as an option. 

same here. I read your devlog about the game and thought I'd give it a try but no mac version. I'm pretty new to godot but my impression was it's fairly easy to cross publish. maybe that's not true in practice, but you should look into it.