Karnov is a traditional platformer in which the player assumes the role of the titular Russian strongman. The game features 9 levels in which Karnov must fight his way through various enemies and collect treasures. The final boss of the game is often known as "The Wizard". Karnov's main attack in the game is a fireball he apparently shoots out of his mouth.
In the Famicom and NES versions of the game, the story is "enhanced", explaining that the kingdom of peace, "Kriamina" (Creamina?) has been invaded by the devil Arakatai's army. Arakatai appears to be a large dragon, replacing the arcade version's Wizard as the final boss. Karnov is sent by God to restore peace to Kriamina and defeat Arakatai. The game features a wide variety of very strange enemies, including but not limited to skeletons riding ostriches, golden statues which break apart and reform, and what appear to be professional wrestlers. Each stage ends with a boss; these include a fishman who reaches in to a sack for objects to drop on Karnov, a centipede woman, and of course a man walking a lion.
- Jump Boots - Faster run and higher jump.
- Bomb - Kills enemies and reveals secret passages.
- Ladder - Used to find secret areas.
- Boomerang - Kills enemies.
- Super Fireball - Kills all enemies in one hit.
- Wings - Gives Karnov the power of flight.
- Scuba Helmet - Faster swimming.
- Mask - Reveals hidden items.
- Shield - Replacing the trolley in the NES and Famicom versions, the shield blocks enemy bullets.
- Trolley - Kills enemies.
- Red Orb - Triples number of fireballs.
- Letter K - If the player collects 50 K's, they recieve an extra life.