Los Angeles, April 26 : 'The Flash', the DC Comics superhero adventure starring Ezra Miller, was played to a mostly enthusiastic audience at the annual convention of movie theatre owners in Las Vegas. In the lead-up to the debut on Tuesday evening, executives at Warner Bros. and DC touted 'The Flash' as "one of the greatest superhero movies ever made." It may not have cleared those stratospheric expectations (there was a little film called 'The Dark Knight', after all), but the finished product elicited plenty of cheers, laughs and maybe a few tears in the room at Caesars Palace, reports 'Variety'. That said, CinemaCon is hardly the Cannes Film Festival. The audience at the Colosseum, filled with movie theatre owners from across the globe, is one with a vested interest in the success of the blockbuster-hopeful. But showcasing 'The Flash' in this capacity is yet another sign of Warner Bros.' passionate support of the project, one that has been plagued over the years with controversies surrounding Miller, as well as myriad director shake-ups, Covid-19 delays and a regime change at the studio and at DC. CinemaCon marked the first screening of 'The Flash' ahead of its theatrical debut on June 16. In 'The Flash', Miller's heroic Barry Allen travels back in time to prevent his mother's murder, which carries unintended consequences and cracks open the DC multiverse. Prying open those portals leads to all kinds of unexpected cameos - some teased in the trailer and some that Zod would strike the press down for revealing. Suffice to say, nearly every one of these appearances, as well as several sly nods to Tim Burton's original 'Batman', sparked enthusiastic applause from the crowd. Miller did not attend CinemaCon, nor did their co-stars Ben Affleck and Michael Keaton (both returning as their respective Batmen), Kiersey Clemmons or Michael Shannon. But director Andy Muschietti and his producing partner Barbara Muschietti were present to introduce the film, which was described as "a four-year process". The siblings stressed the version of the film that screened on Tuesday is unfinished, "but it's still pretty awesome," Barbara said. There are no closing credits, so it's possible that even more surprises are in store for those who purchase tickets. Earlier on Tuesday, during the studio's hours-long CinemaCon presentation, Warner Bros. Discovery CEO David Zaslav told the CinemaCon crowd that he's already seen 'The Flash' three times. "It's a very emotional movie. You're going to go through all the emotions," he told the room of theatre owners. "It's the best superhero movie I've ever seen." Prior to Tuesday's screening, much of the press around 'The Flash' has been overshadowed by Miller's off-screen behaviour. The actor, who faces assault and abuse allegations, has apologised for their past actions. "Having recently gone through a time of intense crisis, I now understand that I am suffering complex mental health issues and have begun ongoing treatment," Miller said in a statement last summer. "I want to apologise to everyone that I have alarmed and upset with my past behaviour. I am committed to doing the necessary work to get back to a healthy, safe and productive stage in my life." Regardless of their personal issues, the studio has expressed confidence in Miller's performance. As Muschietti talked up the film during Warner Bros. presentation on Tuesday morning, the filmmaker praised Miller as "an incredible comedian" who has "all the action required for a big spectacle like this." Muschietti added, "They wanted to do all the stunts, and I let them." /IANS