Cheat mode:
Press Right, A(2), B, Start at the options screen. Options for level select and invincibility will be displayed.

Unlimited roars:
Press Right, A, B, C, Start at the options screen. The sound of Simba as an adult roaring will confirm correct code entry.

Random start:
Hold Start on controller two and turn on the Genesis to start at a random level.

Hint: Pass through blocked locations:
In the first level where you become an adult (Simba's Destiny), there are three non-passable places that remain that way until you have defeated all of the Jaguars. To get past these without having to defeat all of the Jaguars, simply flip them with the flip move (X, Y, Z). Do this three to four times to get past without defeating all of the Jaguars.