Diamonds and other precious rocks comes from the depths of the Earth. We can't have these rocks if weren't for the brave people that go forth to the dangerous mine. There, they dig night and day, to get a small ounce of gold. They risk their lives because anytime, the cave might collapse on them. That is the danger that most miners are facing just to get the precious rocks. This is why; these minerals are of high value. They won't be of high value if they were easy to get. The world would be filled with these precious stones if that is the case.
This games shows the possible danger that a miner faces, the moment that they are in the cave. The idea here is to get the minerals to the destination point. You would earn money if you do that and you can use the money to buy some upgrades for your truck. Drive as fast or as slow as you want, but one thing that you need not to forget is to drive with safety precaution. Like in a real situation, it is easy to lose a life in this game. You could also lose a cargo because of the trailer getting detach to the truck.