Joystiq [Nintendo]

Karnov is an NES port of an arcade game, both of which star a guy named Karnov who ... flaps his arms around and spits fireballs at monsters in a rocky, ruinous landscape. Okay, having no idea what's supposed to be going on, we checked Wikipedia, which says that he is a circus performer "on a quest to search for treasures." Oh! Well, at least that illuminates one aspect of the game for us -- the story, indeed, does not matter.
What matters is that you're jumping around, collecting K symbols for extra lives and weapons for extra abilities (also you get a ladder for ... climbing up areas) and shooting fireballs. You can pick up stationary fireball symbols on the ground that allow you to shoot formations of two or three fireballs at a time. These fireball items also restore health -- Karnov can take two hits, after the first of which he inexplicably turns blue, and the fireball item restores his human-like coloring.

Karnov is one of the most unintentionally creepy games on the NES. The enemies don't have any consistent visual style -- some have outlines, some don't, some are detailed-looking, and others are cartoonish -- and don't even really make sense. The first boss is a floating fish monster who throws projectiles out of some kind of seed bag around its shoulder. The game's single repeating stage music is a roughly thirty-second loop that alternates between upbeat circus-type music and a more urgent, nerve-wracking tune. This song repeats over and over again through every second of the game except when you complete a stage or die. The death theme is the happiest tune in the game, and the least annoying.
The creepiest thing about Karnov -- something that takes a long time to pinpoint -- is that the monsters make no noise. Karnov's fireball-shooting makes a noise, and using items makes a noise, but the enemies' movements are totally silent. Which, along with the generally bizarre character of the game, lends a horror-movie sense of something just being wrong. The fact that weird technically-motivated decisions like that can affect the feel of the game so much is something we love about the NES. Also that it was, at one point, financially viable to publish this game in large quantities.