The main idea of the book cover is an image of an "impossible architecture". Since the contest allowed the use of stock photo, I searched in Adobe Stock with the keywords "impossible figure". And I saw this.
The original image was small so I extended it to make it more of a fortress. I then incorporated the name of the book to the image by skewing and tilting the text to realistically blend it to the architecture.
The book name is placed vertically while the author's name and "A Novel" were laid flat to the ground.
Furthermore, regarding the colors, I based it on the plot of the book. I read that the boy's main goal was to get a copy of "Playboy". As something sexual, I colored the other side of the fortress with red. The color may also indicate high security or alarm.