*Quick Note - My playthrough ended around the same time as Kreekakon's; not sure how much more there was to it, but here ya go*
Main Menu: Real talk. It was beautiful. Okay Next.
Mapping: For just a single map mod it was good. Not a whole lot of detail outside of 1-2 of the main rooms. A few clipping textures and the wall corners were put together strangely. There were a few cool pillars made up of non-traditional pillar items (i.e. the red sewer corridor pieces) and I thought it was pretty neat. It might have been a weird FOV glitch, or perhaps the camera position in relation to the player was a bit off, but I could have sworn that the walls were bigger than normal (as if they'd been scaled up). The room before the tunnel was well done; quite purdy
Lighting: There wasn't much lighting, but of what little there was, it was good. Spotlights with casting shadows used properly. Not much else to say. The one billboard you used (I'm assuming it was one, hard to tell with "..." sanity and the accompanying screen effects) I was dissapointed with; from what I could tell, it just appeared to be a singular point billboard left with the default color.
Scripting: The screen effects for the intro event looked wonderful, and the events were very well done. Granted, I had no clue what was going on in the one where I started floating and getting attacked, but it was still cool. I loved that statue from Gary - Dark Secrets as well, it was well implemented. Good use of sounds as well.
Story: If you're looking for a mod that takes the most overused and cliche plot and turns it into a work of art, look no further. Even though there isn't much storywise (at least that I was able to pick up) the setting was well established. Um...Yup.
Atmosphere: I don't want to be
that guy; I really don't. Noone likes the "balls of steel" guy. But I didn't get that scared at all. I played it under all the right circumstances, but I couldn't really immerse myself. Oh well. The atmosphere was definitely dark and unnerving, but there was something that just didn't click with me.
Overall: I'm not sure if it competes with the better known names of A:TDD mods, but it can definitely hold it's own and deserves recognition for the quality and originality.