Great treasure still lies deep in the abandoned Crystal Mines. But over the years, underground demons have made them deadly. Guide your robot through the mines, destroying demons and gathering great wealth. Or fail, and become history.

Crystal Mines II is an update of the gameplay in its predecessor; in a nutshell, overhead puzzle-solving best described as Chip's Challenge meets Boulder Dash, with a touch of real-time elements thrown in.

In Crystal Mines II, you operate a robot going through the abandoned crystal mines, picking up crystals and avoiding the underground demons that inhabit the mine. Mine levels are completed when a crystal quota is reached, however the quota is usually not the entire level so bonus points can be obtained by finding additional crystals. Like Boulder Dash, gravity is a factor and affects any boulders, crystals, etc. so they can be used as weapons against demons. There are also deceptive elements, such as "Dormant" demons that look like boulders, that add to the challenge. Finally, the robot has weapons that can be used to eliminate certain obstacles.