So many questions, so little brains. The architecture, as evidenced by the castle textures, is blocky and gothic. Appropriate for a castle, I'd say. Not overtly, but subtly. Again, appropriate since they're both Quake-engine games.
Lighting is there.
The author states that a known bug is that the ending sequence will not work. I question this, as it worked fine for me. Perhaps I am the idiot savant of Half-Life maps, where things that don't work for me work for others, and vice versa. I also have no trouble programming VCRs and hooking up my own stereo. I suppose he means that the end returns after the fade-out.