It is the first time you run FH? or just one day stoped to work?
In the first case, change the rendering sussystem doing this:
To change it open the file Ogre.cfg who is located at C:\FeralHeart. (open it with notepad or any other text editor)
In the first line you will see:
Render System=
Depending on what you have, switch between these 2 lines:
Render System=Direct3D9 Rendering Subsystem
Render System=OpenGL Rendering Subsystem
save the file and check if all is working now.
In the second case:
The magic fix is to Unisnstall the game, then delete the FeralHeart folder and resintall again.