Unfortunately i used Game Maker 8.1 for this, and as far as i know it can't export to Mac.
I could port it to GM Studio, but then i would need to fix a lot. And exporting to Mac from GM Studio isn't something i've figured out how to do yet. It's got a few more steps than i would like.
If i get a mac version of one of my games working it might inspire me to go and port others, but right now i don't have plans to do that. Sorry! :(