Wolfenstein: Blade of Agony is a huge Doom mod 6 years in the making

Wolfenstein: Blade of Agony is one of the biggest GZDoom wads ever made—it may even be the biggest. But "wad" is a misnomer really, because this 30 level outing looks more like an entirely new game. The project has been six years in the making, and during that time 15 volunteer modders from all over the world have put their heads together to create a "true" follow-up to id Software's Wolfenstein 3D.