Hi there, so sorry about this - it appears to be a problem with Big Sur. I googled "You do not have permission to open the application" and saw others with the same issue for other apps, and found a few (easy!) suggestions on how to fix it.
Again, sorry about this, but I've stuck to Catalina and tested it on that and an even older OS and it works fine, so I think Big Sur might be the issue.
I assume this will be the same for all my Mac games, so if you find a working solution please do let me know and I'll gladly add it to the description so others can fix bypass this too!
Many thanks!
QS =D