COGENT released 3D Realms Duke Nukem 3D Megaton Edition, feature updates including Steamworks-enabled online multiplayer, new achievements and integration of additional Duke Nukem 3D expansion packs.
Duke Nukem 3D: Megaton Edition is the definitive compilation of the landmark first-person shooter that includes enhanced versions of Duke Nukem 3D: Atomic Edition and three unique expansion packs as well as the original version of the classic game.
I. Unrar release, mount .iso, install the game
II. Copy fixed files from /COGENT directory
III. Play the awesome game
N.B. : Don't forget to add an exception for your anti-virus program.
Run the game from DN3DLauncher.exe