From the back of the box:
Earthdate: 2264. The renegade Red Lord of Darkness has overthrown the United World government with his army of cyborg fanatics. Millions of political prisoners are being tortured in his infamous Labyrinth of Doom far beneath the surface of the planet. Very little is known about this subterranean maze of brick-walled catacombs. Just vague rumors about the hidden millions in stolen gold guarded by a ruthless band of mutant cyborg zombies commanded by the merciless General Zod. Only one thing is sure.... none of your predecessors have ever come out of this dreaded place alive, But, you must find a way out with a lode of gold big enough to launch the counterrevolution. You are the last hope; the last of the great Lode Runners.