Underworld is for version 1.3. It has 4 levels and the file is 4.3MB in size. The file name is Underwld.zip. Note: The Underwld.bat file would not work for me. If you also have this problem you can right click on the underworld bat file, go to edit, and delete /hUnderwrld.def. If that does not work extract all the files from Underwld.grp using the XGroup/XExtract program found on the home page. Then move them into your Underworld folder. Next rename the maps. Stalker.map to e1l1.map, Cycler.map to e1l2.map, Underworld.map to e1l3.map, and Nasa.map to e1l4.map. Then click on duke3d.exe and go to episode 1. The file was modified on December 15, 2005.

Underworld has fair to good level design and gameplay. There's a new weapon and aliens. The gameplay gets hard at times. I rate it as good with 3 out of 5 stars.