A large map for Doom 1 with lots of secondary corridors and canyons (but otherwise mostly linear gameplay) and tons of bad guys. The Doomworld thread for this wad can be found here: http://www.doomworld.com/vb/wads-mods/41648-big-map-for-doom-1-nice-shadow-effects-thorough-demo/
Credits:
Andy Leaver, for inspiring me to try harder at Doom mapping with the masterpiece called Timelessness, and Sigvatr, for Last Man on Earth, a wad so visually erotic it enticed me into learning how to use GLDEFs (dynamic lights sure are pretty).
Base:
New from scratch
Build time:
Approx 3 weeks with a six month break interjected
Editor(s) used:
Doom Builder, XWE
Bugs:
One poster at the doomworld thread linked above mentioned missing textures, but I don't see any.