This is probably a longshot, but I have a win8 PC for my desktop and a Macbook for my portable. I bought the game on Win8, and I don’t want to buy it twice for my Macbook. Is there any way to avoid paying twice? I have a proof of purchase email from Microsoft.
If you bought the Desktop edition via the Greenheart Games Store (powered by FastSpring), then you simply need to refer to the download link in your receipt email from FastSpring in order to download the game for Windows XP - 8, Mac OS X 10.7+, or Linux. You as also guaranteed to receive a Steam key upon the game’s release on Steam.
If you bought the ModernUI edition via the Windows 8 Store then yes, you will have to purchase the Desktop edition of the game to play it on your Mac. GHG are working to provide Steam keys for Windows Store customers, but can offer no guarantees at this time.
This leads me to believe that you bought the ModernUI edition. You could wait for the Steam release, at which point you may get a Steam key, or you can purchase the Desktop edition from the GHG store.
If you buy from our website you get download links for Mac, Windows and Linux versions and you can use all of them for your own use without having to buy another license.
If you buy from the Windows Store you can use the game on up to five Windows 8 devices but you cannot access non-Windows Store builds such as the Mac and Linux versions.
However, we aim to give both Windows Store players and those who bought from our website a Steam key when the game is available on Steam to access whichever platforms we will support with the Steam release (likely Windows, Mac and Linux).