As I'm reading Uncle Bob's Clean Architecture I keep wondering how all the advice presented can be applied in game development. Games are nothing more that highly interactive real-time simulations and shouldn't really differ that much from any other complex systems. Good practices in architecture design should be as much help here as anywhere else.
That said I have some doubts whether obtaining a high level of coupling between game engine and its logic can be easily obtained. Game engine is basically a framework so "Frameworks Are Details" rule should be of use here but from what I see games are practically inseparable from their underlying engines. I haven't seen any use of Clean Code rules in most projects I've encountered. I've heard than even unit testing is a rare occurrence.
How can I even achieve loose coupling if all important subsystems like event handling, physics, renderer and even main loop itself are baked in the engine?
Or should I ignore this since an engine is not a database and it'd be highly unlikely to think about changing it as the project goes by?