I downloaded the game and it ran just fine on my mac, so it's probably some missing files on your end. This sometimes happens to 7z archive files in macos due to the security implementation.
Here's what you can try:
1. Try re-downloading the game but using the pixeldrain link:
You must be registered to see the links
2. After opening it, move the files to the documents folder instead of the application folder
If it still doesn't work, I'll be releasing an update for the launcher soon with some bugfixes that might help.