I have absolutely no idea, I don't have a mac and I don't have any intention of getting one any time soon. But none of the functions I've used are Windows-specific so it probably should just automagically work thanks to the GM sandboxing? (I'm really careful with those edge cases that breaks compatibility these days)
The one thing that could be an issue is the special rendering trick used to make you sink halfway through tall grass, but you could work around that by using draw_sprite_part and only draw half the player when you're in tall grass.