Mortal Kombat Advance

Hidden Characters
There are three hidden characters in the game which can be unlocked through playing the game in a specific difficulty level. These characters will not stay permanently unlocked and will disappear when the game is reset.

Smoke (human):

Beat the game on Warrior. On a new game menu, Smoke will be available on the character select screen.

Motaro:

Beat the game on Master. On a new game menu, Motaro will be available on the character select screen.

Shao Kahn:

Beat the game on Supreme Master. On a new game menu, Shao Kahn will be available on the character select screen.