Warp labyrinth

Legends speak of the world before this one, where people lived in a humongous cavern, with an infinite tunnel onto near-nothingness occupying half of their view at all times. Somehow, these people were stuck to one wall of this cavern, and never in danger of drifting into that endless, sparkling abyss. But it was a fragile, impermanent world, and a fickle god destroyed it all, releasing the people from the force restraining them and filling the abyss with fire. Only those who had predicted this day and built this new world in preparation survived the destruction of the old world.

Rules

No gravity. Everything exists inside an extensively-carved mansion door.