Within the source code is evidence of unused Treasures of Shao Khan which were to be reward options after beating the single-player mode:

• REWARD IS THE OPPORTUNITY TO WITNESS THE INNER ANIMAL ALL WARRIORS POSSESS.
• YOUR REWARD IS THE OPPORTUNITY TO WITNESS THE CHILD IN ALL OF US.
• YOUR REWARD IS THE OPPORTUNITY TO WITNESS THE KIND SPIRIT WITHIN ALL WARRIORS.

These appear to have been Finisher Demonstration compilations, dedicated to Animalities and Friendships, respectively.