From the manual The object of Diamond Mine is to drive your Subterranean Mining Vehicle through each mine shaft, pick up the diamonds, process them in the special Diamond Processing Area, and take them out of the mine shaft without being killed. You begin the game with five vehicles. You don't have to worry about cave-ins, black-lung disease and ordinary dangers like that. These are special mine shafts in which many different types of monstrosities lurk. They have no intention of letting you escape with their precious diamonds... and will stop you if you let them.