A low-budget Chinese animated film that was widely mocked for its crude visuals became a viral hit, with people packing cinemas to see just how bad it is.Niu Lai, which translates to "Here Comes the Cow", earned around 7,000 yuan (US$1,000) in its opening week from Aug. 5, before surging to 33.06 million yuan at the Chinese box office, according to ticketing platform Maoyan.

The film, made by a mother and son, follows the journey of a calf named Niu Lai and was crafted frame by frame over five years, local media reported, with the duo also composing original scores for the end credits.

Caelan Moriarty, an American musician working in China, told AFP the film is "so bad that it's so good".

"I appreciate how bad it is, but there's some heart [put] into it, so you can't hate that," the 25-year-old said.

Artificial intelligence (AI) could make the movie in "like ten seconds or even faster", Moriarty said, but "the fact that they didn't use AI, they took time" was impressive.