Sonya: back, back, forward, b.
Frost: down, down, back, a.
Scorpion: back, back, forward, a.
Kung lao: back, back, forward, b.
Kano: back, back, forward, a.
Fight as Kano
Successfully complete arcade mode under normal difficulty setting.
Fight as Kitana
Successfully complete arcade mode under the very easy difficulty setting.
Fight as Quan Chi
Successfully complete arcade mode under the very difficult difficulty setting.
Fight as Shang Tsung
Successfully complete arcade mode under the difficult difficulty setting.
Fight as Sub Zero
Successfully complete arcade mode under the easy difficulty setting.
Get Shang Tsung With Koins
To get shang tsung with coins gather 7500 koins or more and go to the krypt. There find the coffin named FF and have 7500 koins or more. Open it and you will unlock shang tsung.