In most stories, Nobita is a crybaby who relies entirely on Doraemon. However, Steel Soldiers showcases his growth. He makes a mistake of cosmic proportions, but instead of running away, he stands up to fix it. His bond with Zanda Claus (and the robot "Pippo") is the emotional core of the film. Nobita teaches the robot that life isn't just about following orders; it's about feelings.

While other Doraemon movies like Stand By Me focus on nostalgia, Steel Troops focuses on . The Robot Army believes order is everything; emotions cause chaos, so emotions must be removed. Nobita and friends argue that pain, sadness, and even fear are what make life worth living.

The film pivots from a fun robot-building adventure to a chilling war movie. We watch Nobita, Doraemon, Shizuka, Gian, and Suneo fight for the survival of humanity. The tonal shift is jarring, beautiful, and heartbreaking—especially when you realize the fate of a mysterious blonde boy named (or Riruru).