From publisher blurb:
Ride the beanstalk and crawl into the sprawling halls of Castle Gargantua. There awaits the most legendary of giants and the fiercest creatures known to man. Delve further than ever for the great doors of Castle Gargantua have swung open once again, and what lies ahead isn't for the faint-hearted.
The biggest dungeon ever published by the OSR. A campaign, a massive generator, and a grotesque setting all-in-one.
It's not about killing monsters, looting treasure, and gaining experience as you delve deeper into some mad archmage's architectural folly. It's about surviving in a loathsome, terrifying environment where nothing is quite as expected. It's about atmosphere, gloom, and despair. It's a thriller.