I was going to say the pk3 itself is already standalone and can run with gzdoom just fine, but I actually forgot the maps were separate from the pk3 itself as MM_Levels.wad (I was updating this so many times in 2021 that I really got tired of importing and exporting the maps wad file over and over), while running both the pk3 and map wad together in gzdoom would still work perfectly fine, I still went ahead and updated the download to have the maps added into the pk3 for convenience.