Ultratech is a very powerful company which organizes a tournament called Killer Instinct. Along with regular participants, experiments Ultratech created also fight in the tournament. Ultratech also discovers a technology to make bridges between dimensions and also release from his dimensional prison a two headed monster called Eyedol, an ancient warrior that was locked away along with his rival.
One of the best fighting games that I've played. Solid Graphics, great sound, and addictive gameplay were what really pushed to this to one of the better fighting games that makes this a good game to play even to this day.
Rumor has it that Rare is in the midst of making another Killer Instinct sequel (of course it would be XBox/XBox 360 exclusive since Microsoft now own Rare)
What I also loved about this game was its very unique character sensitive "No Mercies" (kinda like a fatality). For example, if you did Thunder's uppercut "No Mercy" against TJ Combo you'd see his gloves fall to the ground after he disappears off-screen ... However if you did this same ending move on Glacius he'd turn into icecubes and if you did it against Sabrewulf, he'd turn into a can of dog food.
Of course, the most famous ending move was Orchid's flash. She'd unzip her top and flash her opponent causing all her male opponents causing the male opponents' eyes to zoom out of their head cartoonishly before they die of a heart attack or pass out (not really sure which).
Like some of the other No Mercies it was character unique so that when you flashed Orchid, she'd simply fold her arms and kick the dirt in disgust.