Sorry to hear that >.< Unfortunately, I don't own a mac or know anyone who does, so I can never test mac builds properly :( Which makes fixing bugs on mac extremely difficult.
Is it that the button to access the save menu isn't there? Or does it not show the save/load screen when pressed? Or something else? :o
Either way, what's currently available of the game is pretty much like a short demo, so you should be able to experience all of the content without needing to access the save/load system provided there aren't any other bugs in the way preventing you from proceeding with the story.
I'm actually working on the next update at the moment, and my code from back when this initial episode was released is pretty awful! I'm going to have to rewrite most of it I reckon because it's just so messy and impractical to work with going forward with the new content.
I'm also changing a lot of the UI and stuff while editing the old code before I get into adding the new content. So it's possible the issue will be resolved once I have the new update out. I can't put an exact time on when that will be though cos there's a hell of a lot of work to be done since I've essentially gotta remake what's already released + add a brand new character and other stuff. I'm aiming for the end of spring, but things might not go according to plan.
I'm also hoping to not need to have black screen fix builds in the future because I'm not gonna bother having the video background title screen going forward since it causes issues with some people's computers. It'll be easier just to have 1 build with a static title screen background rather than exporting 1 with video + 1 with a regular png file.
Please still let me know in more detail what it is that's preventing you from accessing the saves though, and I'll try and look into it to see if I can fix it for the next update :3