Wolfenstein 3D's winding journey from pitch to release
gamedeveloper.com
gamedeveloper.com
I went back to play the other episodes a few years back and it's interesting how far he was able to push a Wolf3d-style engine. There's lot of interesting little details and extra gameplay tweaks like the vending and slot machines. But it's a rough game to play in its entirety due to repetition.
columns = colors