From this map, the player can choose between accessing the second secret map (by exiting to MAP32: Grosse) or returning to 'normal' Doom II gameplay (by exiting to MAP16: Suburbs). A faithful remake of the first level of id Software's Wolfenstein 3D, right down to the textures on the walls and the inclusion of the bonus level-exclusive Wolfenstein SS enemy type, 'Wolfenstein' was designed by Sandy Petersen and uses the music track 'Evil Incarnate'.
MAP31: Wolfenstein (MAP33 in GBA) is the first secret map of Doom II and can be accessed via MAP15: Industrial Zone.
