I may be new to the forum, but I'm not for Marathon.
I could probably bring up all sorts of mentions, in fact especially in M2D & demo Mi; rather, I will say that the general style/fact of Marathon architecture/lighting/textures/etc. has been with me for as long as I've known Marathon, rivaling the attention and consumation I had (now dormant) with the Story Page. I have dreams, not usually of any particular Marathon environment, but the idea of one. M1, M2D, Mi.
I can even say that I prefer the architecture/lighting/textures/etc. to the combat, although together they become something so..... I can't describe the feeling.
I want to make a game/scenario for Marathon (actually A1) just to show my love of the whole of Marathon, although scenarios always don't inspire the same thing as Bungie Marathon.
P.S. Pathways scares me too much though (seriously!)