This was the most expensive South Korean film production up to that time.
Although this was a South Korean film production, the cast was made up of Occidentals in the hopes of getting a very lucrative U.S. release. Even with a re-release with upgraded special effects and a new title ("Reptilian"), the film only achieved a U.S. release on home video and some cable TV showings.
The original 1999 cut of the film that was shown in South Korea had unfinished CGI due to lack of funding.
Most of the main cast of the film was hired from America and England, while the extras were mostly cast from foreigners working in South Korea, many of whom had no experience on a film set. The South Korean production company placed ads in English language newspapers for extras and many showed up, were given a quick screen test, and then some were hired, mainly based on if their schedule allowed them to take part, not on acting ability. The South Korean director spoke no English and, during the shoot, had to use an interpreter to make the main actors and extras understand what was needed.
There was an update to the film's special effects, but the updated version was never released on VHS, Betamax, DVD, or Blu-Ray.