Descent 3

You play the role of a mercinary hired by a Post Terrain Mining Corporation (PTMC) to reclaim their mines from a strange alien intellegence that has somehow invaded all their automated systems and caused all of their robots to go berzerk and kill all the workers. You blast your way thru the mine on your way to the mines Nuclear core or Boss robot. In Descent 3 there are different mission types: Data Aquasition, Retrieval missions, rescue missions, etc. Awesome game. Descent 1 came out right after DOOM 1.. It was way ahead of its time in a way. Download the demos from www.interplay.com and find out for yourself, these games rock.