It's a doom 2 level one replacement for a single player on a single skill. Done in an hour or so. Super fun to play, super high play value. High, very high play value.
Credits:
God and his magic workings. And Tim Watts over at Id software.
Base:
New from scratch
Build time:
1 hour
Editor(s) used:
DOOOMBuilder v1.65, XWE 1.15, Windows XP (notepad).