Here is the recent leaked build of 3D Realms infamous lost shooter, Duke Nukem Forever, from 2001.
Here are the basic installation instructions, taken from the Twitter account @EduardoBruwurbs. He has more advanced instructions for other things relating to DNF 2001 on his Twitter.
1. Select all the .rar files and extract them to a singular folder of the same name as the regular name of the .rar files by right clicking on the selected files. (This option should appear if you use Winrar.)
2. Upon extracting, copy the contents of Patches/MegaPatch/ into the october folder, and then run October 26/System/DukeForever.exe
Press kit: https://anonfiles.com/p0e3O0e3y8
Original thread: https://arch.b4k.co/v/thread/598471840/