"Hope" by Na, whose low-budget horror movie "The Wailing" became a huge hit in his home country, was able to give free rein to his dark imagination in this gory tale of alien invasion."It's the most expensive film in the history of Korean cinema," Na told AFP in an interview at the Cannes Film Festival where the film premiered on Sunday night."It's a film that really required a very, very large budget because of the special effects, the design, the actors."Despite having a genre-defying concept that was hard to sell initially -- it skips between thriller, sci-fi, horror and comedy -- he received backing from Korea's Plus M Entertainment and a budget of around 30 million euros ($35 million).The cost of "Hope" underlines the increasing resources available to South Korean directors whose hit films such as the quadruple Oscar-winning "Parasite", as well as TV series like "Squid Game" have turned the home of KPop music into a global entertainment centre.Reviews for "Hope" were broadly positive, with Screen magazine calling it "a thunderously entertaining genre mash-up" while The Hollywood Reporter said it had "instant cult classic written all over it".But others such as IndieWire slammed the quality of the special effects -- suggesting the budget was "not enough" for Na's grand ambitions -- while its run-time of 160 minutes was described as "over long" by Variety.