There is a patch to compile all master levels into one .wad file here
, and it works in zdoom and shows a menu in doom 2 to select to play Doom 2 or the Master Levels. When i use with doomsday, that option doesn't appear, so i assume that doomsday has made their own menu system or something.
Is there anyway to put the menu in with a .def file or something like it shows up in zdoom? or even a custom command to allow the games menu to show in game instead of what doomsday has made?