Urban legends will be part of it, as well as more "traditional" mythology - vampires, fae, sorcerers, et al.
Though I will warn you that I'm not planning on dipping into horror, since the story is mean to be a comedic murder mystery in the vein of films like Clue, Murder By Death, or (arguably) Knives Out. Not to discourage you from trying it out, of course! I just didn't want you going in without knowing what you were getting in to.
I just noticed that, for some reason, the tagline wasn't showing at the top of the page, so I rectified that!