I see the playing field populating and players taking their turns... 
Special thanks for this particular challenge opportunity. Full disclosure, I've actually never played Doom. Which made this first week a research exercise. Sorry JohnC and crew, but wow...I'm put back in anticipation of what may be to come from the quantity of declared participants. So tally-ho, everyone in on the ride.
I'm going the raycaster route to stay more in key, with an old wolfenstein clone framework from an early gameinstitute.com, Perlin Noise and AI Seminar offerings by Author : JohnDeGoes(12-15 years ago). One of the graphics items Doom brought to the table were textures on the ceiling and floor. A concept my chosen framework is unaware. This go, I'd like to do a proper AI agent type or two. Also on the todo list is a simple sprite animation atlas tool that is feed from targeted screen grab so I can render the art instead of doing pixel art or photo persuasion, but mostly hand packing image sequences is such a chore.
I'd like to open this project up to others. Right now I'm thinking heavy guitar loops for game play. It would be nice to have a sound guy of the programmer persuasion and an ai guy. Lets talk.
...but after kicking the can for more than a while, the flame piddled out. I've had this project collecting dust for a decade and thought it would be a good idea to start from wolfenstein to transition to doom. Then I was umm...whatever, I've done enough 2D...moving onward.
Here I'm showing the abandoning and rebirth starting with a nice modular wall asset gem from the unity store and a first stab at some licks. Makes me happy.
?