Sorry for the misunderstanding! >.< Just to be completely sure. Have you tried putting the "Fix_Permissions.command" file into the game's folder? (The folder with credits.html file and the unknown program icon)
Might be silly to ask that, when you did or do put the "Fix_Permissions.command" file into the game folder. Try to double click that command to run it or right click and/or ctrl+click and choose open on "Fix_Permissions.command"
(optional: If that doesn't start the game, make sure in terminal that command has +X permission to run. Then try opening/running "Fix_Permissions.command"
If all else fails above after opening "Fix_Permissions.command" then try to possibly open the unknown program icon instead if the above with the command was done right.
(Sorry if it's a lot of trouble to go through, this might be stuff you've already did or tried and if so do let me know. I can try to reach out to "Ben" on our discord and ask them if there's a critical step missing to get things working. I wish I had more personal support myself with Mac os or understanding. >.< )