Many viewers in Venice fell for the movie’s audacious mix of genres: It’s a monster movie, a Cold War thriller, social-issues drama and even, at times, a musical. Del Toro said his win was a vindication for monster movies, science fiction and other sometimes-derided cinema genres. “This is a beautiful encouragement, a beautiful act of love, and I think it is something very necessary,” he told reporters. “It’s about time that we understand that you cannot only legitimize certain genres” and not others. The 74th edition of the world’s oldest film festival brought stars including Clooney, Matt Damon and Jennifer Lawrence to the canal-crossed Italian city’s lush Lido island. Del Toro’s film was one of several in the lineup that looked anxiously at humanity’s treatment of the Earth and one another. Similar concerns showed up in the small-town rage depicted in Martin McDonagh’s “Three Billboards Outside Ebbing Missouri”; in the spiritual agonies of Paul Schrader’s eco-drama “First Reformed”; in the migrants fleeing war, drought and hunger in Ai Weiwei’s documentary “Human Flow”; and in “mother!”, Darren Aronofsky’s wild parable of Mother Earth under attack. The festival’s runner-up Grand Jury Prize went to Israeli director Samuel Maoz’s “Foxtrot,” a compelling study of a family’s grief and the way trauma echoes through the generations. Maoz, who won the Golden Lion in 2009 for his war film “Lebanon,” has received some negative reaction in Israel because “Foxtrot” is critical of the army, the country’s most respected institution.