Here's why:
* Dark and suspenseful atmosphere: The novel explores the dark side of human nature and the psychological impact of bullying.
* Complex characters: The protagonist, Marty, is a troubled and damaged character, making the story unpredictable and keeping the reader engaged.
* Focus on psychological tension: The novel delves into the motivations and inner thoughts of the characters, creating a sense of unease and suspense.
* Unexpected twists: The plot unfolds with unexpected twists and turns, leaving the reader guessing until the very end.
While it has elements of other genres, like coming-of-age and crime, the core of "Bully" is its psychological suspense and the chilling portrayal of its characters' inner struggles.