We've gotten an incredible number of messages regarding this one, so we thought we'd address it!
Mac and Linux support are, unsurprisingly, stretch goals still to come. Even if we were to use a multiplatform engine, such as Unity or MonoGame, a completely new speech recognition system needs to be implemented, and additional suites of testing.
Still, we want as many people as possible to be able to play There Came an Echo! Even if the stretch goal isn't reached, we'll do our best to make it happen. No guarantees, but we *are* typing this on a Mac, so.