Acting is not the best and the "historical period" and "fictional present time" are not well depicted, full of prejudices about an interesting time in Spanish history that could have been treated much better. Good news are that if you take the story as something completely fictional and ignore the history bit nuisances, you can enjoy kind of a "parody" of spy movies, science fiction, eternal youth experience with very nice 60's-70's Spanish pop music and the contrast between a time where people speak to people and have respect vs current cold, tech-driven society. So see it if you like something different but do not take seriously the historical facts.