BEIJING • At first, the director of Shanghai Fortress took the blame when the movie, touted to follow in the footsteps of successful sci-fi film The Wandering Earth, failed to take off at the box office.

In a post, Teng Huatao said he was fine with criticism of his work in the past, but he was now despondent that the backlash had widened to claims that he had brought shame to the country.

He noted that netizens were accusing him of closing the door to Chinese sci-fi after The Wandering Earth forged a path forward. Saying that he was very sad, he added that "as director, I've ultimate responsibility and I am very sorry".

Shanghai Fortress tracks the efforts to ward off alien invaders. With the movie even failing to make the top 10 list on Wednesday after it opened on Aug 9, Teng has drawn further criticism beyond the initial brickbats over special effects and plot.

This time, fans of Lu Han, who stars in the movie, which cost an estimated US$57 million (S$79 million) to make, are upset that Teng has shifted some blame to the singer.

According to the 38jiejie portal, Teng said he had made a mistake in casting Lu in the role of a commander that was not "suitable" for him.

Lu's fans said it was unprofessional for Teng not to back his actors. They added that it was not entirely Lu's fault if he was paired with an older actress - Shu Qi, 43 - and that the two did not generate much chemistry on screen.

Amid the finger-pointing, more level-headed pundits are asking for a stocktake. A commentator on China.org.cn wrote: "It's not the end of the world... (Shanghai Fortress' flop) is a great lesson to learn. The difficulties facing Chinese sci-fi film-making include lack of genuine talent, original stories, industry chains, venture funds, vision and imagination. These need to be further explored and nurtured over a long journey."