Famous levels

Level 0 is an expansive non-Euclidean space, resembling the back rooms of a retail outlet. All rooms in Level 0 share the same superficial features, such as worn mono-yellow wallpaper, old moist carpet, scattered electrical outlets, and inconsistently-placed fluorescent lighting. 

Level 1 is a massive warehouse with concrete floors and walls, exposed rebar, dim fluorescent lights placed on the walls and a low-hanging fog with no discernible source. The fog often coalesces into condensation, forming puddles on the floor in inconsistent areas.