Well here's another solution...
I have a Windows computer and for download I have to download TWO things in order for FeralHeart to work. First you have to download the download that says, 'FeralHeart game setup'. So yeah you download it and yeah its done when you see the three paw prints as in icon. BUT WAIT! That's not all. Then you have to download the download that says, 'FeralHeart patch' and wait for it to download. When it's done, you drag it onto the icon with the three paw prints.
Did you only download one or both? (At first I only downloaded one and it always said, 'FeralHeart.exe'. Now that I downloaded both, it works perfectly c;