Undying Fortress
Release date: Dec 18, 2025
Developers: Choice of Games
Publishers: Choice of Games
Genres: Adventure, Indie
Categories: Single-player, Adjustable Text Size, Color Alternatives, Keyboard Only Option, Mouse Only Option, Playable without Timed Input, Steam Cloud, Family Sharing
Supported languages: English

Can you and your magic sword save the kingdom from death herself? Infiltrate a tower full of skeletons, decipher its secrets, and escape with your team! Undying Fortress is an interactive dark epic fantasy novel by Yeonsoo Julian Kim, author of The Fog Knows Your Name , where your choices control the story. It's entirely text-based, 500,000 words and hundreds of choices, without graphics or sound effects, and fueled by the vast, unstoppable power of your imagination. For centuries, a mysterious fortress has floated above the kingdom of Serendal. Now it has fallen—and all of its secrets, treasures, and monsters are within reach. You have fallen, too. After expulsion from the Imperial Academy cut short your studies as an aspiring knight-scholar, you turned to the life of a mercenary. Wielding your family's legendary blade, Wicked Fate, has won you a certain degree of fame and fortune, but now the ancient fortress presents the opportunity to climb much much higher. Enter the tower with a motley group: fighters, spellcasters, and thieves; former friends and mentors from the Academy; even a prince of the realm. Within lurk countless skeletons, shambling Afflicted, ferocious flying creatures cobbled together from bones, and more. Commanding them is the fearsome Carrion Mother, an ancient deity long suppressed by the royal family. Only you and your companions will learn the secrets that Serendal's rulers want to keep hidden. Fight off undead monsters to protect Serendal, or learn to wield forbidden mortuary magic and get the creatures to do your bidding. Uncover ancient secrets that may shake the realm to its core, or keep them hidden and become the power behind a new throne. Win glory with your magic sword and prove that you are worthy of knighthood, or just gather treasure to come out of this the wealthiest mercenary who ever lived. Play as male, female, or nonbinary; gay, straight, or bi. Choose your specialty: weapons, stealth, magic, negotiation, or scholarship. Romance a mercenary comrade-in-arms, a loyal and confident swordswoman, a spellcaster friend-turned-rival, a trickster prince, a cursed guard, or even a terrifying necromancer. Fight bone wolves, shambling undead, and other horrors to reach the heart of a magical fortress. Unlock the secrets of ancient magic to command an army of skeletons. Shatter the boundaries of time itself to right ancient wrongs and cross dimensions to rescue your friends from the land of the dead. The Undying Fortress awaits!