LOS ANGELES - Big-budget action film "Alita: Battle Angel" may have garnered lukewarm reviews, but the filmmakers behind the manga-inspired movie envisioned by James Cameron say they are delighted with how it has turned out.

The movie from 21st Century Fox about a cyborg heroine in a post-apocalyptic world has been more than 15 years in the making with a budget of between $150 million and $200 million.

Co-producer Jon Landau said the makers would not judge its success by box-office numbers and felt they had delivered the movie they wanted.

"We are our biggest critics," Landau told Reuters. "If we're happy with the movie, we've done our job. I think not only are we happy with it, but James Cameron is happy with it and (manga creator) Yukito Kishiro, who could be our biggest critic of all, is thrilled with it."

Cameron, the director of Hollywood's $2 billion blockbusters "Avatar" and "Titanic," first wrote a script for "Alita" in 2004 but handed the movie over to director Robert Rodriguez in order to focus on 3 long-delayed sequels to "Avatar."

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Hollywood entertainment website The Wrap reported last week that "Alita: Battle Angel" was expected to take in a modest $25 million over 5 days when it opens in North America on Feb. 14.

Cameron said 2 more "Alita" movies based on Japanese writer Kishiro's graphic novels were mapped out if the first film does well.

Rodriguez said the biggest challenge in making the movie was finding the right actress to play the lead part of Alita, a wide-eyed young angel of death played by Rosa Salazar, with CGI effects.

"We can put up all the scale and spectacle on the screen, but if we don't have somebody to carry the heart and empathy of the movie? Rosa was the shining light that showed us the way," Rodriguez said.

"Alita: Battle Angel" also stars Oscar winners Christoph Waltz, Jennifer Connelly, and Mahershala Ali.