The planet is called Niflheim. In Norse mythology, this is a realm in a permanent state of Winter, the afterlife for those who do not die a heroic death.
While it's well known that Pattinson plays multiple versions of Mickey due to the cloning process, what many don't realise is that director Bong Joon-ho insisted on filming certain key scenes without Pattinson knowing which version of Mickey he was playing until just before shooting. This method was meant to capture the confusion and existential dread of a clone struggling with his own identity, leading to some of the film's most unsettling and raw performances.
The release of the film was delayed for almost a year due to internal wrangles over which cut was going to be released. Ultimately, Bong Joon Ho won that particular battle with his final cut being the one that was released to cinemas.
Robert Pattinson uses accents to differentiate between Mickey 17 and 18, likening them to Ren & Stimpy. In his audition, he used the voices of Johnny Knoxville and Steve-O from Jackass.
The film's creepers were designed by Bong and Jang Hee-chul, who has been collaborating with Bong to create monsters for his movies since The Host (2006).