The game is a scrolling fighter typical of the genre and era, with up to two heroes
featured at once. It was seen by many, at the time, as Data East's
answer to the Technos Japan hit Double Dragon. The player uses a
combination of kicks, punches and jumping to defeat the enemies
(a single hit of any kind is enough to defeat most common
enemies).
The game acquired cult status based on its tongue-in-cheek scenario, including an introduction by the Secret Service agent: "The President has been kidnapped by the ninjas. Are you a bad enough dude to rescue the President?"
Karnov makes a cameo appearance as the game's first boss (screenshot #6 on this page). The background music during the fight with him is similar to the main theme in Karnov as well. The NES instruction manual claims the reason Karnov is working with the "ninjas" is a mystery. (Wikipedia)