ExtraMana is a single Map, indoor/outdoor hybrid. Created using GZDoom in Boom format. For instructions on how to use .wad files here: http://doom.wikia.com/wiki/How_to_play_or_start_wads
Personally i would recommend using a Sourceport to open .wad files instead of the command line.

Mod developed by: ExtraMana

Mod originally hosted on Moddb (developer page): 
http://www.moddb.com/company/black-lagoon-company