I know you said you won't make the game for mac, but could you try with the demo? I really want to try it out but my computer is a mac. Maybe just try and see how much it might grow if you add a mac version.

+1 - if you need assistance with build chains, I have some experience with Unity and other frameworks. outside of that, it depends highly on your render pipeline. simple, pretty-but-fast-render games like this tend to have a good audience w/ Mac users.

yeah, man. This looks like it could be an amazing Mac Game considering the crappy games that Mac gets access too this would do well with the Mac gamers trying to get by with what they got. 

This would be a great game on the Mac, for all the reasons listed above. I avoid flight simulations specifically because I don't want to deal with a Windows PC. I am also developer who has used Unity on the Mac, and this game would be a good fit since you're not exercising rendering hard.