Hello!
If you're a mac user you can actually play the game directly through the itch app: https://itch.io/app
We're not sure why the ZIP isn't working when downloading it directly from here, but if you'd like to play it download the app and install the game through the itch application. It should work then!
We'll make a build where this isn't an issue for the future, but we think it's a security issue with mac computers.