Feral Heart was originally made to run on Windows operating systems and then wrapped for Macs by Shell Prisoner as it states in the "Big help thread" and in the download section. Quote from Red:
This game was in first hand made for windows computers.
Macs run differently from Windows computers such the DirectX rendering system that Feral heart uses, and how files are placed. Without the game's source code, it's probably difficult to make a Mac version that works more efficiently. Here's the Feral heart Mac thread if you haven't seen it already: http://feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=3251.0 (http://feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=3251.0) (I apologize for only lightly explaining this... I do not use a Mac OS, so please correct me if something's off.)
or you could build a better one if you remake feral heart plus.
FeralHeart+ is not an official download, like Feareh said; it's a fan-made version of Feral Heart that is in progress right now to iron out the glitches, etc.
EDIT: Look at this! Nice thread on Mac tips and tricks:
-Via Crossover, not Wine.
http://feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=121 (http://feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=121)