Earlier failed attempts to bring the comic book character to a live action film involved Juan Piquer Simón, Juanma Bajo Ulloa, Alejandro Toledo and Daniel Calparsoro as possible directors.

[1] None of them came to fruition and, following the entry of Pau Vergara [ca] in the project (as producer and tentative director), the direction was eventually tasked to Antonio Hernández.

[1] At some point Álex González and Elsa Pataky were slated to star as lead characters Capitán Trueno and Sigrid but they left the project.

[8] No member of the cast attended the presentation of the movie in Valencia on 5 October 2011, leaving producer Pau Vergara [ca] alone.

[11] Even the president of the Academy of Cinematographic Arts and Sciences of Spain (Enrique González Macho [es]) raised his opinion on the matter, deeming the film to be a 'drag' (pestiño).