Adjective
unfilmable (comparative more unfilmable, superlative most unfilmable)
Not suitable or able to be filmed.
Gilliam abandoned the project because he decided that Watchmen would have been unfilmable. Source: Internet
Card has called Ender's Game "unfilmable", "because everything takes place in Ender's head", and refused to sign a film deal unless he could ensure that the film was "true to the story". Source: Internet
Lack of film adaptation At the Los Angeles Times Book Festival (April 20, 2013), Card stated why he does not want Speaker for the Dead made into a film: "Speaker for the Dead is unfilmable," Card said in response to a question from the audience. Source: Internet