Descent 3 - the last part of the game Descent released on June 11, 1999. The game is extensive, has 15 levels, the player takes on the Resource Keeper of the corporation PTMC (SZ 1032), which aims to stop the nanovirus and recover his money from Samuel Dravis, head of the staff of PTMC.
Image source: http://www.descentbb.net/viewtopic.php?t=10350
Gameplay: