I already loved They Came From Beneath the Sea! so when this game was announced on Kickstarter, I jumped in immediately because classic Brit horror is one of my favourite film genres. If you always wanted to play a game set in a film by Hammer or Amicus, this is the RPG for you. The Archetypes, Trademarks, Tropes and Quips reflect the genre perfectly.
If you know the Storypath (or even old WOD) system, the mechanics will already be familiar, with the various traits offering enhancements (bonus dice/successes etc.) to rolls. The liveblood, however, are Cinematics, which offer a fourth wall breaking way for players to directly affect the given situation. As you play not only a character but the actor playing that character, you can ask, for example, for a retake of a scene, for a standin/stuntperson to take over from you, for a means of escape because the set is made of cardboard, or introduce a missing scene that explains why you suddenly have that much needed flask of holy water you didn't have before, among others.
The Clue system used here means that the action is always moving along as PCs always find what they need to succeed. None of the "You didn't find a particular document/piece of information so this doesn't work" nonsense that plagues Call of Cthulhu etc.
Another special concept in this RPG are scenarios with the option that PCs exist in both the past (18th/19th century) and the 60s/70s of the 20th century whose actions can influence each other or provide insights/memories in certain situations. This is a brilliant way of using stories with long-lived/resurrected villains, lingering curses or hauntings and the like. It can also be used as a framework for portmanteau style campaigns (Dr. Terror's House of Horror, The House that Dripped Blood etc.).
The plot hooks, monsters and the two scenarios at the end of the book provide excellent starting points for both one-shots and longer campaigns so this book certainly has everything you need to run the game.
As with TCFBtS!, each chapter is preceded by a piece of brilliantly written, appropriately hammy, short fiction which serve as both scene settings and scenario ideas.
If this made you curious but you're unsure if you want to fork out for the core book, this jumpstart is cheap and contains the base rules as well as a fun scenario featuring satan-worshipping nuns.