Mountain King is a challenging platformer for the Colecovision where your goal is to collect valuable diamonds, outsmart cave bats, and escape a deadly spider in order to retrieve the crown. The game takes place in a multi-level diamond mine where you need to locate several steps before you can reach the crown.
The gameplay involves navigating through the mine, collecting diamonds, and avoiding obstacles such as the flame spirit, skull spirits, and flying cave bats. You must use your flashlight to spot hidden objects like treasure chests and the flame spirit. Once you have the flame spirit, you need to offer it to the skull spirit to gain access to the temple where the crown is kept.