Descent: Levels of the World is compiled from submissions for the 1995 Levels of the World Contest, arranged by Interplay and Computer Gaming World. Several thousand entries were submitted, and winners were voted by CGW and Parallax employees. On the first release of Levels of the World, 123 missions were included. Another 20 missions were made available on Interplay's website and included in the later Descent Anniversary Edition and Descent I & II Complete Collection (where it was bundled along with Descent Mission Builder 2, DMB 1 was released as a stand alone, commercial product originally).
The winners of the competition won I-O Virtual Reality headsets.