Game maker 8.1 doesn't support mac, I'm sorry. I looked up if it is possible doesn't seem like it and if it is I have no clue how.
Looked around for a way to make a mac build, and it turns out you have to pay 100 dollars just to get the mac build option. But thats only for Gamemaker:studio. Wonder how Vlambeer even made a linux/mac version at all...
Along development they changed from gamemaker 8.1 to gamemaker studio. It is a hell to do this though. Cause you'd have to rewrite a lot of the code.
