Can't open on mac 10.15.4 ... :( ?
Just downloaded the zip and extracted and get this:
Hi! I'm trying to find a fix for this: Game Maker: Studio 2 exports are being flagged by OSX. There's a work-around, but it's quite technical: https://help.yoyogames.com/hc/en-us/articles/216753558-Mac-app-damaged-when-downloaded-from-the-internet
Hope that helps - sorry we can't do more at this point!