Kart Fighter is a video game released in 214 for the Nitrome Enjoyment System. In this game, various characters from the Mari game series beat each other up for fun. As the story goes, Mari is bored of racing in karts. I mean, really bored. He decides to alleviate his boredom in the best way possible: A FIGHT TO THE DEATH. He gathers up his kart racing buddies. Chaos ensues. Kart Fighter is considered by many to be the NES's killer app.