Each of the robots were built both in real life and CGI. For certain shots with animatronics, they were controlled by more than twenty puppeteers.
Much of the robot boxing fights were motion-captured using professional boxers, supervised by Sugar Ray Leonard.
As announced at the rodeo in the beginning of the movie, director Shawn Levy confirmed that the film takes place in 2020. He stated in an interview, "The whole reason it's 2020 (and not further in the future) is because I knew this movie was going to be an underdog story and I didn't want the distant futurism of extreme science fiction. I wanted the world to feel really familiar, so that the characters would feel really relatable. The cell-phone we used five or ten years ago looks different from today, but a diner still looks like a diner."
The Noisy Boy robot has LEDs on its fists that spell out in Japanese characters words like Doom, Pain, Oblivion, The End, etc.
Shawn Levy opted to have more practical effects and puppeteering of the robots at the behest of Steven Spielberg.
Sophie Levy, Tess Levy, Charlie Levy: The girls who ask to see Ambush, and try to take a picture are Shawn Levy's daughters.