This is indeed planned :) Patrons are promised a key, it'll also be sold here - I'm waiting until the web tool is a bit more fleshed out to develop the standalone.
And Mac support is definitely going to be a must since I develop on a Mac :D
Hey! Just letting you know, there actually is a way to play this on desktop, and it works for Windows, Linux, and MacOS! You just need to install the itch desktop app and install the game through there. Hope this helped!