Was one of several films around the world that were the first to use an entirely "digital backlot" (i.e. the actors were all shot in front of blue- and green-screens with all the backgrounds added in post-production, a technique which has been used for TV, video and video game production for many years). Fans debate on which movie was shot first, but the other movies include: Sky Captain and the World of Tomorrow (2004), Casshern (2004), and Sin City (2005).
The patient being treated by Doctor Emma Turner wears a shirt printed with Enki Bilal's artwork.
Nikopol's first name in the comics is Alcide.
Based upon the first two volumes of the Nikopol trilogy, Carnival of the Immortals and The Woman Trap. Many characters and plot elements were changed or added for the movie.
The poem Nikopol is reciting in his first scenes is "Une charogne" (The carcass) by Charles Baudelaire.
The book that Jill is reading in Paris is "Les Fleurs Du Mal", by Charles Baudelaire. It talks about paradise, love, death, time, exile, among others themes, all referenced during the movie.