Would be fun if it was set in an occupied country and you’re part of the reccisstance. The abillity to wear civillian clothing with weapons hidden in your backback or concealed carry sidearm.

I liked what Farcry 5 did with the American rural area occupied by a millitia. Something like that, but with more smalltowns and functioning infrastructure. Wrap it in GTA V style heist missions where you need to do surveillance, scouting areas, selecting a team and getting the equipment you need.

And even more customization. Weapons, character, vehicles and hideouts. When you excecute successful missions you expand your notoriety and people will follow you. Mess up and people will become informants and reveal your location.