Based on a novel by Orson Scott Card, Ender's Game takes place in a futuristic Earth that is still reeling from an alien attack five decades earlier. Convinced the aliens (called 'Formics') still present a threat, the International Military, led by Col. Hyrum Graff (Harrison Ford), have launched an operation to train the best and brightest young children in the hope of finding a mind capable of winning the next great war between humans and Formics. Graff becomes convinced this mind belongs to Ender Wiggin (Asa Butterfield), a brilliant misfit with just the right balance of compassion and killer instincts. Graff's hunch leads Ender to battle school, where he is tasked with mastering difficult war games, completing intellectual and psychological tests, and establishing himself as a respected leader among his peers. Eventually, he is expected to command his own fleet of soldiers in a very real war. If Ender's Game is anything, it's efficient. The film feels like a series of strategic moves designed to produce the optimal outcome, much like its protagonist acts on the battlefield. While it fails to impart the same level of emotional impact as its source novel, director Gavin Hood (X-Men Origins: Wolverine, Rendition) has a no-nonsense approach that refuses to condescend to a young audience by whitewashing matters of war, politics, or the training of young children to become soldiers. Although the movie suffers from a weak script, Butterfield and his co-stars, most notably Hailee Steinfeld (True Grit), do admirable work with the material. Butterfield's smallest gestures -- a ghost of a smile here, a furrowed brow there, his unfailingly tense posture -- give Ender's Game some much needed soul. While his role is small, Suraj Partha also excels as the serious, loyal soldier Alai. Another challenge presented by the book: Most of the story takes place in battle school and revolves around rival teams of children ("armies") playing simulated war games in a lavish zero-gravity training room. This could have easily dragged, but Hood, if anything, amps up the pace and turns the games into some of the film's most interesting scenes. Battle school is a world with its own internal politics: those within the child armies, and those within the higher ranks. Harrison Ford, Viola Davis, and Ben Kingsley make up those higher ranks. Surprisingly, it's the veteran actors' performances that highlight the screenplay's weaknesses. Davis is largely relegated to mournful glances in Ender's direction as he is stripped, piece by piece, of his innocence, while Ford alternates awkwardly between gruff yet benevolent father figure and cold, unfeeling military strategist. Kingsley, in the role of a legendary war hero named Mazer Rackham, has a complicated facial tattoo that seems to exist to imply battle-hardened moral ambiguity in place of an actual performance. Despite its drawbacks, Ender's Game is a visually spectacular, tightly paced film that is certainly a win in terms of adapting a seriously complicated novel.