What do Resident Evil, World of Darkness, and Deadspace all have in common? They, like many other games, have the label of HORROR put upon them, when that is not what they actually are. Sure, they are all good, and yes, they may be scary at times, but they are not true horror. These are games of Action, Intrigue, and the Supernatural, with elements of horror. A true horror game is one that you have no chance of beating, only surviving. And only if you are very lucky. Horror comes from sense of helplessness, not a struggle to over-power the darkness.
Amnesia, Silent Hill: PT, and Call of Cthulhu are all true horror games, where at best, surviving through the game is your only hope. Heck, even Five Nights at Freddy's is even in this category, even if it is all about jump-scares.
Up until now, Call of Cthulhu has been the only tabletop RPG I could find that truly immerses it's players in an atmosphere of dread. Unfortunately I have never been much of a fan of Lovecraft's work.
Belly of the Beast is a truly unique and horrifying game, played entirely within the digestive tract of a creature the size of mountain, still consuming the land you once called home. You have no chance of escape, no chance of ever seeing daylight again. There will be betrayal, there will be insanity, and there will be horrors. Welcome to the Belly of the Beast.