The premise of Star Fox 2 is markedly different from its predecessor: Instead of following mostly linear paths inside predefined missions, the player moves a team of two ships freely around a map screen that represents the Lylat system. When the player's ships make contact with enemy forces, the game switches to an action perspective, piloting the Arwing ship directly with controls and game play similar to the first Star Fox. When the player clears the specified objectives, he or she is taken back to the map screen to select a new destination.
Although Star Fox 2 was complete, Nintendo cancelled the 1996 release due to the impending release of the Nintendo 64, the desire to use the most advanced system available for a new Star Fox game, and competition changing expectations of 3D games. The game received its first official release as part of the Super NES Classic Edition microconsole
Source: Wikipedia, "Star Fox 2", available under the CC-BY-SA License.