Hell yeah, I love this! I think this is a beautiful work of cosmic horror. The indescribable nature of the Evil, the gradual progression of the loss of sanity... it all evokes the feelings I love from this genre. I think the choice of making it about a single protagonist that we all share was a really good pick, I have rarely seen it but I think it contributes to that feeling of separation characters often feel in this setting.
The Creeping Menace mechanic is also so interesting! The randomness the die bring lends itself to having games with vastly different pacing which makes replayability much easier, as it does the vagueness with which you describe the Shadows and their actions on the world. Fantastic work!
My favourite parts are the "Allowed Shadows" table (SO interesting, and useful, to portray so many different sources of unease that gradually increment in danger) and the "Neurosis" examples (especially the degradation that occurs if you get to read more than one line!).
Also from a reader's standpoint, the fact that it had hyperlinks made it much easier for me to understand what was going on, haha.
Anyway, thank you so much for this, can't wait to play it!