I watched a $500K sci-fi thriller starring AI actors. The movie made me feel something real — for a moment.

• Higgsfield AI made a sci-fi action thriller called "Hell Grind" starring AI actors.
• The movie cost around $500,000 to produce.
• I went to a screening to see how it held up.

For a brief moment toward the midpoint of the AI-generated film "Hell Grind," I caught myself experiencing something unexpected: genuine emotion.

As the male lead, Roco, gazed at a photo of his recently kidnapped love interest, he flashed back to memories of them growing up together in an orphanage. The sadness and yearning felt real.

The sensation didn't last.

Mid-flashback, Roco and his AI-generated costars began laughing in an eerily synchronized fashion, their eyes peeled wide open. As I sat in New York's Metro Private Cinema this week, scooping up handfuls of popcorn, the uncanny valley of AI came roaring back.

Generative AI has crept into a variety of corners of the entertainment business this year, spooking many creatives who worry what it could mean for their jobs. While post-production teams are turning to the technology for de-aging and other effects, some actors in short dramas are already losing out on roles to AI characters. The shift is a top concern for the actors' union SAG-AFTRA, which approved new contract language this week that pushes producers to bargain over the use of synthetic performers.

"Hell Grind," which takes AI usage to the max, sprang up in May at the Marché du Film in Cannes (a side event that's not the famous Cannes Film Festival). The brainchild of startup Higgsfield AI — which runs an AI platform for creatives, brands, and marketers — it was conceived as a way to show the tech's potential as more than just a tool for making short videos. The company, which crossed a $1 billion valuation earlier this year, spent around $500,000 to produce its 95-minute film, with much of its budget going to computing costs. While AI regularly shows up in bits and pieces of Hollywood productions, "Hell Grind" is the highest-profile film made entirely with AI-generated visuals.

Higgsfield tapped a group of in-house creatives and outside filmmakers who used highly specific text prompts (typically around 3,000 words) to generate around 100 hours of content, which was edited down. The company did not use AI to write the script, except for a few short filler moments, which Higgsfield's CEO, Alex Mashrabov, told me he thought were noticeably less effective in the film.

The result is a visually impressive movie with a passable plot line, landing somewhere between a video game and an effects-heavy project like "Planet of the Apes."

"It's a new workflow, and it's also very important for us so that we show to the world what's possible," Mashrabov told viewers at the screening this week. "The production process looks different where it's actually possible to go back and iterate with AI and deliver exactly the emotion which the creative director was envisioning."

At various points during "Hell Grind," I was taken out of the story when a character did something that just felt … off. The way Roco held a slice of pizza in one scene looked like it was his first time encountering the food, for example. The synthetic children in the movie generally creeped me out, and the AI-generated voice work didn't always feel consistent (one character seemed to flip between a British and American accent, for instance).

Still, it was hard to shake off the feeling that talented AI prompters may soon be coveted players in Hollywood.

While I wouldn't expect to see AI actors or writers playing a big role in the making of films like "Tár" or "One Battle After Another," it feels like this technology will be hard to resist for budget-sensitive executives angling to speed up movie production. That's especially true in genres like action and sci-fi, where visual effects budgets can be a big constraint. And the technology may open doors for independent filmmakers who have grand ideas but small budgets.

"Budgets and opportunities are not equally distributed across the world," Mashrabov said. "Hopefully, this will spark the next generation of creativity."