Sabrewulf was originally planned to transform back into his human form as a weakness.

The original Killer Instinct Arcade game calculates the damage inflicted on an opposing player through a random number generator. Generally, light attacks cause 3-6 points of damage while heavier normals range between 15-19. The value for causing a dizzy state, however, remains a constant.

There are two unused voice clips in the game's files, announcing characters named "Heatshade" and "Pyrotech". These were intended for the character select screen and were early names for Cinder.

Killer Instinct was originally titled "Brute Force", with the name being changed much later in development, along with that of most of the characters. All of the characters except for Jago, Glacius, and Eyedol went through at least one name change over the course of development.