Complex sentence: The popularity of "We Are Not Angels" expanded beyond Serbian borders, even to Croatia, where the film turned into a huge underground attraction and gradually became part of the popular culture, most notably through various slang words that became part of urban vocabulary.
Split into simpler sentences: The popularity of "We Are Not Angels" expanded beyond Serbian borders. In Croatia, the film turned into a huge underground attraction and gradually became part of the popular culture, most notably through various slang words that became part of urban vocabulary.