Okay so it seems like Apple has changed how developers can hand off software in Catalina and basically made it impossible to give someone software without heavy restrictions and a paid developer account.
This is very disappointing, I don't currently have one but I'll consider getting one as I do want Mac users to be able to play the game.
I was able to work around it by downloading the itch.io app and launching the game through there. Sorry I know that's inconvenient and you've probably already gone through a lot to troubleshoot things but that's a way to play the game right now.