Hi, sorry to hear that - can you check your security settings as described here? You may need to allow the app to open from Security & Privacy as described at the bottom of that page. Let me know if that helps!
Thanks for replying! I tried to look into Security & Privacy pane, but there is no button there for me to press. Also the alert shown with the error message isn't the same error shown when an app is from an unidentified developer.
I dug into the mac logs and found this, hope it helps!
Apr 21 19:48:57 MacBook-Pro com.apple.xpc.launchd[1] (com.apple.xpc.launchd.oneshot.0x100004cf.The Messenger Assist[73231]): Could not find and/or execute program specified by service: 13: Permission denied: /private/var/folders/n4/qhwt0jjx6dq69pkt47vhl5_40000gn/T/AppTranslocation/C77E4054-70BB-4352-938B-C358FF4DA98C/d/TheMessengerAssist_MacOSX.app/Contents/MacOS/The Messenger Assist
Apr 21 19:48:57 MacBook-Pro com.apple.xpc.launchd[1] (com.apple.xpc.launchd.oneshot.0x100004cf.The Messenger Assist[73231]): Service exited with abnormal code: 78
I appreciate the additional info! I've updated the mac build to hopefully resolve the issue. If you're willing to give it another shot, try downloading a fresh copy of the game. In researching this a bit, I've read that another potential issue is that the game may not work correctly if you use an app other than the default Archive Utility to unzip it.