Jinborov Karnovski (also known as the titular Karnov), is a Russian circus strongman who is collecting all of the pieces of a treasure map so he can become a wealthy man. This Lost Treasure of Babylon is being guarded by the evil dragon Ryu. While the gameplay is basically the same as the other versions, the story for the Famicom version is different. It involves Karnov, who comes from a small town called Cleamina, being called by God to be his envoy. Karnov is tasked with getting rid of the evil troublemaker known as Alakatai.

Karnov features nine stages of side-scrolling action. Karnov's main attack is to breathe fireballs at his enemies. Karnov can collect power-up orbs which can increase the amount of fire he can breathe out. Karnov is also able to jump, with the height being increased by collecting boots. Other items Karnov can carry and use include bombs, ladders, boomerangs, clappers (which destroy minor enemies that are currently on the screen instantaneously), and shields. Occasionally, Karnov will be able to make use of certain items such as wings which let him fly in the air and a scuba gear helmet which lets him swim underwater. Also, scattered throughout the stages are K icons. Collecting 50 of these will reward Karnov an extra life.