HONG KONG — What will Hong Kong be like a decade from now?

When his new film “Ten Years,” which answers that question with five dystopian tales set in 2025, was denounced as a “thought virus” by the Chinese state-run newspaper Global Times, the Hong Kong director Ng Ka-leung was unfazed.

“If anything, the editorial brought mainland Chinese people’s attention to our small production,” said Mr. Ng, who is also one of the film’s two producers.

“Ten Years” has become a surprise hit across theaters in Hong Kong, tapping into fears in the semiautonomous Chinese territory over the erosion of local culture and civil liberties, fears fed most recently by the disappearance of five people connected to a Hong Kong company that publishes political books banned in the mainland. Since its general release in late December, most showings have been sold out. With a budget of about 500,000 Hong Kong dollars, or about $64,000, the indie production had raked in nearly 5 million Hong Kong dollars by Thursday, Mr. Ng said. On Friday, it received a best film nomination for the Hong Kong Film Awards.

“We didn’t even spend a dollar on promotion,” he said. “We initially thought we were only going to show it in private screenings and had never expected such huge demand.”