Creating atmosphere?

[palistov]

The best advice I have for creating atmosphere is to pick an appropriate ambient sound. It sounds like you used a sewer ambient sound file for this map, but this place looks nothing like a sewer. If you wanted to have that drippy, damp watery feel, add some water drop particles and maybe some lower-level areas flooded with water.

There is a lot more to atmosphere than just sound. Lighting, the interplay between light and dark areas of the level, shadows, particles systems, billboards, fog, and even silence all work together to create the "atmosphere" in levels.