Trivia: The restaurant near the bookstore where Charlie works is called the Double Deuce. Double Deuce was the name of the Road House in the 1989 film version.
Trivia: SPOILERS: There are two credits sequences. In the first sequence, Sonic encounters a group of Metal Sonics that try to kill him. However, he is saved by Amy Rose, a character from the games. A post-credits scene shows Shadow's feet walking up to a crater where one of his gauntlets landed, revealing that he survived his apparent demise.
Trivia: The first time Maika Monroe saw Nicolas Cage in make-up as Longlegs, her heart rate jumped up to over 170 bpm, around 100 above her resting heart rate.
Trivia: Chip, who plays the role of Alfie (Ellie's cat), is the pet cat of Claudia Schiffer, the wife of the film's director, Matthew Vaughn.
Trivia: Willem Dafoe previously played Max Schreck (and by extension, Count Orlok) in Shadow of the Vampire, which is a fictionalized telling of the filming of the 1922 Nosferatu film.