It's a game, we've got that much figured out. To put it into simple terms, it's a maze exploration games where your goal is to reach the center of the maze to battle the final boss. Along the way, you can pick up weapons and will have to defend yourself from other enemies scattered throughout the large maze.
The game is set in the open air, but the 150 meter tall walls on the sides forbid any exit attempts in that manner. The maze has actually been carved into the ground, which explains the thick, bulky, and rough nature of the walls.
The actual algorithm to generate the maze is called Eller's Algorithm, written in C#.
More information will come later, such as specific mechanics and more.