MarsRiders for Mac

From deplastic:

A group of former outlaw miners have become gem robbers. Considered by both the Earth and the Mine Federation as a dangerous troublemaker gang, they have tried to capture them over and over again. However none of them has ever been seized alive, so they are still regarded as a legend. With no posssibility of ever going back to Earth again, their only hope is getting the control of the black market and through their riches turning Mars into their own realm on the fringe of the Earht's laws.