Mac version has been updated! Try the download again and see if it works for you now. :)
Not quite sure what you mean. There isn't a save button at the bottom of the screen for me? When I use the save button from the top of the screen it brings me to the save slots but then everything freezes. I'm not able to save and the return button to go back to the game can't be pressed either so the only option is to force quit the game.