Recycled Script: A more literal example in that the storyline of this game is basically a recycling of the backstory that was going to be used for Tremor in Mortal Kombat 3. Mortal Kombat co-creator John Tobias revealed in an interview that "I do remember having big plans for Tremor, but when I conceived him, he wasn't a member of the Black Dragon. He was a Lin Kuei hired as muscle by a mad man who was trying to open a gateway between Earth and Outworld." In Special Forces, in addition to the aforementioned changed of making him a Black Dragon member the mad man he would be working for would be Kano.
Stillborn Franchise: This and Mortal Kombat Mythologies: Sub-Zero were intended to branch MK out of fighting games and into action/beat 'em ups. The pair of games' negative reception kiboshed that until they tried again in 2005, and this game was retconned out of existence.
Tobias had planned on doing several other platform spinoffs with the intention of expanding the mythos of the series, two specific ones he had hoped to create would be centered on Liu Kang and Kung Lao and another with Baraka as its protagonist. Though following the poor reception of Special Forces and Tobias's departure from the franchise, all other endeavors with the exception of Mortal Kombat: Deadly Alliance were placed on hiatus with former project not being realized until 2005's Mortal Kombat: Shaolin Monks.