I see you have a Mac version on Itch - any chance to get one on Steam, too? (The Steam version is Windows-only ATM.)
the back end for Steam makes it incredibly difficult to have versions for multiple platforms, (or do anything really) and because the number of mac users is relatively small, it's been easier to just have it on itch.io until there's really enough demand to have to go through and do it. Same goes for an android port.