I think the terrain shader isn't working properly on mac - it stays as a solid block even when I move, so I can't see any of the things under it. Love the idea though!
I'm so sorry to hear so
To be honest mac computers have long been an issue, due to the way the terrain is being generated. It appears to work on most mac computers, including the one I test from, but sadly at this point I'm no longer in a position to verify how playable is for all mac configurations.