A question on design

[Froge]

What is it about the Amnesia maps that make them feel so much more dynamic and immersive than most maps in mods?

First I thought it was the amount of variety in environment. So I put a lot of different ceilings shapes and walls. Then I thought it had to be the detail. So I loaded up my maps with particle systems and billboards and diverse lighting and scripts that triggered scary sounds / events (like lights going out).

My maps still feel so static and boring.

What's your opinion on the genius in design of the original Amnesia maps?