Hmm... I know there have been some changes to font api stuff in OS X over the past few versions, so it's possible that is the cause. Any reason you haven't updated OS X to the latest version?
I did not update to Yosemite because my iMac slow down dramaticaly when I try this version. Also, I loose all my albums in the new iPhoto and the old version is not available with Yosemite.
So I reinstall my old back up with Maverick OS.
Thanks FPV Freerider if you can solve this font API problem in the next release. FYI The first release of the game works very well with Maverick, and I love your game!