Can you run other games from here? Do you know if they're all code signed?
Yes, I never had this issue with other games on itch.io. Only issues I had before is when I don't have permission to play a game, but I have been able to solve that. And about code signing, I don't know what that is so sorry!
I have confirmed that apple won't allow apps on catalina that have not been codesigned unless you jailbreak your computer.
I'll try to get that done next week. It is quite bureaucratic.