Do you have a Retina display on your Mac? There's a known incompatibility in SDL that will cause this problem. We're still working on a permanent fix, but as a workaround for now, follow the instructions under the heading "How do I adjust the resolution of my Retina display?" here:
Change the selection next to Resolution to "Best for Display" and run the game again. If this doesn't work, set it to "Scaled" and experiment with the various scalings below (Larger text ... More space).
Follow the same instructions as the question above.
Send us the game log as follows:
Note: if you can't find the container in step (4), open the library again as in step (3) and navigate to Application Support » InterAction studios instead. If you see game files there, then you're running a very old version of our games and we would strongly recommend you upgrade to the latest version before proceeding.