Audiences flocked this weekend to see the film version of "Ender's Game," the 1985 a sci-fi novel about a child who goes to Battle School to learn to defeat an alien enemy.

Entertainment Weekly's Grady Smith reported that the film dominated the box office this weekend. He also noted the adaptation scored particularly with male audiences over the age of 25. Most of the audience was a curious group of Millennials, who read the books as children and wanted to see them come to life on the big screen. That small interest group may not be enough to launch "Ender" into franchise territory. Critics generally said although the film was visually entertaining, at its core it lacked substance. The film scored a 61 percent on Rotten Tomatoes.

"There’s been considerable debate about the conflicted themes and messages of 'Ender’s Game' over the years," wrote Andrew O'Hehir at Salon. "At its core, Card’s book is about the psychic connection between war and child abuse, two of the worst things that happen in human society. That whole aspect of the story is not half as memorable as the tormented Christ-like ego of Ender, an abused child who is simultaneously victim, villain and saint — history’s greatest war criminal and the shamanic conduit to a vanished race."

Peter Paras wrote at E! Online that the story is one of tolerance.

"Ender is the furthest from a typical alpha male and he's bullied for it. A lot," Paras said. "We were definitely rooting for him to overcome the bullying of testosterone-pumped jerks like his Salamander commander Bonzo Madrid who, incidentally, is former 'Hannah Montana' star Moises Arias. The former geek's 180 turn as an evil teen is as weird to witness as Miley's latest antics."

Paras also pointed out the balance of business and pleasure leans toward defeating the enemy and away from any budding romance between Ender and Petra (Haliee Steinfeld), unlike similarly targeted tales penned by women, which tend to focus on love.

Card will be writing more stories in Ender's world, the Los Angeles Times reported.

"It's for a (young adult) audience," Card said in a video. "It’s about what happens to Battle School after the International Fleet loses its purpose of war."

Users at deemed the movie appropriate for viewers 12 and older, as some of the themes and violence may not be appropriate for younger children.