The film was not a success in Japan, opening at the bottom end of the top 10 films of that week. Conversely, it broke box office records for a CGI animated movie in China, in much the same way that two other US produced Japanese based films had done. Both Dragonball: Evolution (2009) and Speed Racer (2008) had tanked in Japan but went on to be hugely successful in China.
Isaac Asimov's "Three Laws of Robotics" are referenced a few times throughout the film. They are first mentioned when the RRF are introducing themselves to Astro. The laws, paraphrased, are as follows: 1) A robot may not harm a human being, or through inaction, allow a human to come to harm. 2) A robot must obey orders given it by a human being, as long as doing so does not conflict with the First Law. 3) A robot must protect its own existence, as long as such protection does not interfere with the First or Second Law.
The Japanese release of the movie uses the original character model of Astro Boy, maintaining the original bodyform, facial features, and hairstyle rather than the updated character model. The differences can be noted in a comparison between the U.S. and Japanese trailers for the movie.
In summer 2006 the Hong Kong animation firm Imagi Animation Studios picked up the property as part of a three picture deal with Warner Brothers that also included TMNT (2007). Colin Brady was attached to direct. When Summit Entertainment took over the distribution rights in 2008, Brady had been replaced as director by David Bowers.
In 1999, Sony Pictures Entertainment purchased the film rights to Astro Boy from Osamu Tezuka Productions, intending to produce a combination live-action/animatronics/CGI feature film alongside Jim Henson Productions originally slated for a Christmas 2000 release, with Eric Leighton (Dinosaur) attached to direct. This came to no result, and in June 2004, Leighton was replaced with accomplished animator Genndy Tartakovsky (Dexter's Laboratory (1996), Samurai Jack (2001)) with a scheduled 2007 release. However, some time after this announcement was made, Tartakovsky left the film to produce The Dark Crystal (1982)'s sequel, The Power of the Dark Crystal, also for Jim Henson Productions.
Initially Imagi Animation Studios wanted to redesign the shape of Astro Boy's face to make him look a little bit more grown-up. Tezuka Productions objected to such changes. Eventually a compromise was achieved whereby Astro Boy's face was only slightly altered to make him look a little more adult.