I'm looking for a picture book with a Where's Waldo style I was reading when I was a child in early 2000s.
You had to find the "main characters" of the book: a boy, a girl and 3 anthropomorphic books: a blue one, a pink one and a rather grotesque green one.
You also had to find the word "EXIT" somewhere on the double page in order to go to the next double page.
The double pages were also filled with plenty of characters from other popular stories and each double pages had a theme like horror (ft. the Frankenstein monster, the Phantom of the Opera, Dr. Jekyll/Mr. Hyde, ...), pirates (Robinson Crusoe, the Treasure Island, ...)