Brian Adler of Obsidian posted information about a bug with the OSX Beta version.
More information.Hey, everyone. We are aware of the crashing problems on Yosemite right now. After talking to some other projects that are using Unity for their engine the problems may not be unique to our game. We are going to continue to look into it and hopefully it will be something we can resolve on our side and not something that will have to wait for a Unity fix. Thanks for your patience.