From the publishers blurb:
The Maze is a flexible, 464-page mega-adventure that easily adapts to OSRs, dungeon crawls, and any d20 system.
The purpose of this massive adventure is twofold: to enjoy "Break the door" one-shot scenes, but then following them up with an overarching plot that offers you myriad possibilities for fun. The essence of the game is to have characters die easily, so only the luckiest, strongest, most clever ones can survive in The Maze's environment and discover its mysteries. Let your characters perform epic deeds, and seek an awesome and legendary last stand.
Additionally, the adventure is a challenge for the Maze Master because they have to roll everything randomly during the session. In an ever-changing Maze, the adventure leans heavily on improvisation (or really careful planning) for both players and Maze Masters.