Can't open it on Mac. (MacOS Big Sur 11.7.3, MacBook Pro Retina 13-inch Late 2013, 2.8 Ghz Dual-Core Intel core i7, Intel Iris 1536 MB).
You can follow the steps in this video or use the itch app!
Sadly this issue will never go away because our game isn't signed and notarized and Apple really doesn't like that :)
Try downloading the itch desktop app (https://itch.io/app) and launching the game through there. I'm on a Mac and it almost always works for me!