The novel has received negative criticism for violence and its justification. Elaine Radford's review, "Ender and Hitler: Sympathy for the Superman", posits that Ender Wiggin is an intentional reference by Card to Adolf Hitler and criticizes the violence in the novel, particularly at the hands of the protagonist.[2] Card responded to Radford's criticisms in Fantasy Review, the same publication. Radford's criticisms are echoed in John Kessel's essay "Creating the Innocent Killer: Ender's Game, Intention, and Morality", wherein Kessel states: "Ender gets to strike out at his enemies and still remain morally clean. Nothing is his fault."[3]

The U.S. Marine Corps Professional Reading List makes the novel recommended reading at several lower ranks, and again at Officer Candidate/Midshipman.[17] The book was placed on the reading list by Captain John F. Schmitt, author of FMFM-1 (Fleet Marine Fighting Manual, on maneuver doctrine) for "provid[ing] useful allegories to explain why militaries do what they do in a particularly effective shorthand way."[18] In introducing the novel for use in leadership training, Marine Corps University's Lejeune program opines that it offers "lessons in training methodology, leadership, and ethics as well [...] Ender's Game has been a stalwart item on the Marine Corps Reading List since its inception."[18]