"As the director, I have an inescapable responsibility ... But I still hope there is a future (production) and that Chinese sci-fi films become better," writes Teng.

A similar statement on Sina Weibo came from novelist, and the film's scriptwriter, Yang Zhi, better known by his pseudonym Jiang Nan: "To those who don't like the film, I am sorry that it didn't live up to your expectations."

The movie is adapted from Yang's eponymous novel, which chronicles a 22-year-old recruit's crush on his beautiful commander. Both serve in an elite unit that seeks to resist the alien invaders. For some critics, the original story's romantic core is one of the main reasons that the movie failed to shape up as an epic depicting an interstellar war, as suggested by the film's trailers.

For some industry insiders and analysts, the flop of Shanghai Fortress offers a lesson for those planning new sci-fi films to avoid similar pitfalls.

"The Wandering Earth has largely raised the bar for Chinese sci-fi movies, as well as public perception of such movies, but The Wandering Earth and Shanghai Fortress are both just single cases. It's unfair to link one movie's performance to an entire industry," says Rao Shuguang, president of the China Film Critics Association.

He says sci-fi films are different from middle-budgeted genres, such as comedy and romance, in that they need persistence and the development of better cinema technology in China.