A bit over a year ago, I suddenly remembered about Doom WADding, went to look up what the community was like these days and started a map as an experiment. Things got a bit out of hand, and now I find myself with an entire episode of seven maps, including some custom monsters, a new weapon, some added gameplay concepts, and whatever else I felt like trying out at the time. It's not quite a total conversion, but I ended up replacing about half the game through various mods.
Optimistically subtitled "Episode 1", this episode has you venturing into the Vulkan power plant - a UAC side project that seemed like a promising source of geothermal energy until, as usual for them, they accidentally drilled into hell and released an army of darkness. Have fun!
Spoiler: More screenshotsEven more screens: http://imgur.com/a/aPprV
Thanks to all in the ZDoom and Realm667 communities for their answers to my questions over the course of making this, and for providing great resources!
Effects and weapons from Brutal Doom by Sgt Mark et al, through a cut-down library that I'm calling "BDLite"
Music from the Doom Metal V4 pack
Monsters and code from resources by
ZRRION THE INSECT
DOWNLOAD (for GZDoom 2.3.2 and above)