Speaking to SYFY Wire, Chinlund spoke extensively about how the smallest detail in the film was carefully added to ensure that the world Reeves envisioned was fully-realized. From the tiniest clue only seen in the background of a shot or the complex, torturous traps created for his victims, they were determined to show how hellbent the Riddler was to enact his exact plan, much like his costumed adversary.
“Not only did we have to make all that stuff, but Matt had to conceive all of that incredible detail. So we were designing ciphers and a whole interface for the computer and the thumb drive sequence and the build for the rat maze… We were hoping that the impact would be one of just sheer awe at the relentless drive that the Riddler brought to his mission in the same way that Batman brought that drive to his mission. And, for me as a filmmaker, [the drive that] Matt Reeves brought to his mission, trying to bring these worlds to life. I think it really is a visual representation of the relentless madness of the character.“
Arguably one of the neatest aspects of the film for avid viewers is the ability to actually solve the complicated riddles Nashton leaves for Batman. The Zodiac-like cipher and the handwritten notebook used by the Riddler were “incredibly detailed and sort of obsessive-compulsive,” according to Chinlund, who adds that, “We had to develop a language, a physical written language.” Not only appropriate for the Riddler, but it is also an immersive tool Reeves and co. utilizes to its full potential.
https://www.slashfilm.com/959906/the-batman-crew-was-relentless-in-building-the-world-of-the-riddler/ The Batman Crew Was Relentless In Building The World Of The Riddler