It was compiled for me by my wife's brother-in-law and this is indeed what he said. It wouldn't run on his wife's Mac.
Viewing post in Uncle Mortimer's Secret comments
I recommend downloading the free trial version of CrossOver for Mac to run it most easily. The free trial download is fully functional and works for 14 days. I bought a license years ago to play Windows IF games like this. So buying was well worth it for me. But the free trial may be enough for you to play this game :) It is a great game.