A few years ago we put together a free roleplaying game of Cthulhu Mythos horror called NEMESIS, using the One Roll Engine of Godlike, Monsters and Other Childish Things, Wild Talents, Reign, and A Dirty World.
Literally infinitely less expensive than most horror games.
NEMESIS includes Greg Stolze’s adaptation of the Madness Meter that he first used in Unknown Armies, Atlas Games’ RPG of occult horror created by Greg and Oath founder John Scott Tynes, and the Madness Meter turned out to be an ingenious addition to the ORE.
NEMESIS is now available on RPGNow and DriveThruRPG, still free but in a convenient place right next to The Unspeakable Oath. Enjoy.