Rockin' Kats, released in Japan as N.Y. Nyankies (ニューヨークニャンキース?) is a platform video game produced by Atlus Software Inc. in 1991 for the Nintendo Entertainment System. The side-scrolling game involves the adventures of a cartoon cat in his quest to defeat a criminal gang that has taken over the city.
The player takes control of Willy, a rising young jazz cat in New York City who goes by the stage name of "The Rockin' Kat." However, the local crime boss, Mugsy, kidnaps Willy's girlfriend, Jill. To rescue Jill and defeat the gangster, Willy must venture through seven different levels or "channels" (from a television set) that feature various themes, thugs and bosses.
Willy is armed with a punch gun, that he can launch at the various thugs, or to hook onto and swing from. Willy can also use the punch gun to grab and throw certain objects. Mastering the punch gun is critical to the player's success in the game.
There are a total of five stages. The first four stages can be played in any order, which are selected at the start of the game as "channels" on a TV monitor. The fifth and final stage or "channel" becomes available only after the other four have been completed. The levels includes a carnival, a flight atop a moving plane, and a park. There's also a "shopping channel", where the player can buy power-ups with cash obtained thorough the game, and a "bonus channel" where minigames can be played for additional cash. A password feature is available that helps the player keep track of their progress.
Source: Wikipedia, "Rockin' Kats", available under the CC-BY-SA License.