There might be a hundred variations of this mod out there. Who knows. Either way, this is my personal take on DOOM with Half-Life sound effects. Any and all sound effects are replaced with Half-Life variations for both DOOM 1 and 2. Only tested on GZDoom and Zandronum, music may not work on other source ports because of utilising MP3s as music. The PK3 file size is ridiculously large (166mb).