Here's another possible (but annoying) way to fix the compatibility problem found on the Unity Forums:It seems to be a normal unity-mac problem. Right clicking the application> Show Package Contents> Contents> Mac OS> (BGP Pre-Alpha, or something similar for the app title)
Open Terminal and type "chmod +x"
Drag your file over to the terminal
If you did this correctly the file image should have changed and the game should now launch correctly.