Actually, there is a way to run FeralHeart again after you've updated your mac, without having to go back to your previous version.
1) Download porting kit. http://portingkit.com/en/ (http://portingkit.com/en/)
2) Once download, open and install, all that good stuff
3) Go to the library tab and drag and drop Feralheart into it
4) Now instead of clicking the actual FH app icon, you can open it by clicking portingkit, then library, then feralheart and play.
It also works for other PC games that may not work anymore with the updated mac version, but that's besides the point.