I'm playing on MacOS but every time I try to open the file I get an error message that just says I can't open the application
You can use this command in your terminal to be able to bypass the error:
% sudo chmod -R 755 /Users/YourUsername/Downloads/Elementallis.app
You need to change "YourUsername" for your username and the location of the game if you haven't place it on the Downloads folder.