The stages "Hakuna Matata" (with gorillas) and "Be Prepared" (in a red-hot cave) were based on scenes that didn't make it into the film. They were created in the game before they got cut from the film. Source: "Devs Play: The Lion King" video with Louis Castle.
This was the last game to be released on the Nintendo Entertainment System.
Developers have said the game was made to be very difficult to encourage people to buy the game rather than renting it and finishing it quickly.