The Glass Staircase

The player controls indentured servant girls Helen, Betty, Dorothy, and Margaret as they do their assigned chores in an empty mansion, following false promises of their freedom. However, three of the girls are gradually picked off by an unseen monster, leaving only Margaret remaining to escape. As written in the game's notes, the girls are test subjects of Dr. Edward Sullivan, the owner of the estate and a veteran in World War I. Upon his return from the war, Sullivan begins to experience a PTSD-induced fever-like "heat" that gives him visions of an eldritch god. This "heat" spreads across the world like a virus and brings forth a cult of fanatics dedicated to the resurrection of this god. With their support, Sullivan surgically resurrects the dead in a failed attempt to provide the god an avatar to possess, littering the mansion's underground laboratory with undead monsters. Margaret fights her way through Sullivan's ungodly creations with a rifle and escapes the mansion's grounds.