its the game that is successful not the software. This game could be written many different ways. Players dont care. Now if there is a particular pain point or glitch in the game and it can be shown that its the style of code that allowed for this to happen. That better organized code would have mitigated this bug then that is important to investigate.

But trying to figure out what a successful game is by its source code is like trying to find what makes a painting good analyzing the chemicals used to make the pigments.