The game's protagonist is called "Rockford". He must dig through caves collecting gems and diamonds and reach the exit within a time limit, while avoiding various types of dangerous creatures as well as obstacles like falling rocks and the constant danger of being crushed or trapped by an avalanche, or killed by an underground explosion.

The player takes control of a commando who is out to rescue his kidnapped family, including his scientist grandfather who is being forced to create a weapon which will give the antagonist of the game, known only as "the Commissar", the power to take over the Earth. In the Sega Mega Drive/Genesis version, the commando, known as Johnny Ford is …