The Lion King is a side-scrolling platformer where players control the protagonist, Simba, in the events of the film, going through both child and adult forms as the game progresses. In the first half of the game, players control Simba as a cub, who mainly defeats enemies by jumping on them. Simba's roar consumes a replenishable meter, and can be used to stun enemies or solve puzzles. In the second half of the game, Simba becomes an adult and gains access to various combat moves such as scratching, mauling, and throws. Simba starts the game with a certain number of lives, depending on the difficulty setting, which are lost if he runs out of health, falls into a bottomless pit, or a lake of water or lava, or is hit by a rolling boulder. Passing through checkpoints throughout the level allow Simba to restart from that point when he loses a life. The game ends prematurely when the player loses all of their lives, though they can continue playing from the current level as long as they have saved the game.
The player can collect various types of bugs. Some bugs restore Simba's health and roar meters, other more rare bugs can increase these meters for the remainder of the game, and black spiders reduce Simba's health. By finding certain bugs hidden in specific levels, the player enters bonus stages as Timon and Pumbaa to earn extra lives and continues. In Pumbaa's stages, he collects falling bugs and items until either one hits the bottom of the screen or he eats a bad bug. In Timon's stages, he hunts for bugs within a time limit while avoiding spiders.