Many of the Haunted creatures in the game are based on asylum patients with specific psychological conditions. For instance, the two-headed Haunteds represent patients with schizophrenia.
There are several Easter eggs referring to earlier Resident Evil games. The first time you see a Haunted in the game (Conelly) plays out exactly as when you encounter the first zombie in the original Resident Evil. Also, the mansion is very similar to the original Resident Evil mansion.
The Keeper, an antagonist with a safe for its head, is an homage to Silent Hill's Pyramid Head.
Directed by Shinji Mikami, creator of the Resident Evil franchise.
"The Evil Within" is another phrasing for "Resident Evil". Both titles mean the same thing.