From playing Mortal Kombat 4, I must believe that Midway's design document went like this.

Step 1: Get With the Times
Mortal Kombat 3's failure was mainly based on how outdated it was. That and the fact that we had chimps writing the code. So let's put Mortal Kombat 4 in 3D, like the SUCCESSFUL Tekken 3. Let's not change the gameplay any, though. Let's keep the 2D speed and style and the incredibly stupid run button. We'll also include a dodge button to further the 3D look.

Step 2: Character Design
Since people pretty much know our character style, let's continue it. The result will be a big mesh of guys we're sick of and guys nobody wants to play as.

Step 3: Gameplay System
We'll keep the horrific style from MK3, only we'll patch it up a bit. The incredibly stupid run button will stay, as will the block button. Characters will be able to draw out weapons, which will be basically useless because they can be knocked out of the player's hands in no time. Their payoff will be when a solid hit lands, the guy will fly up at the screen (a la Teenage Mutant Ninja Turtles 4: Turtles in Time). As stated above, a dodge button will be added. A nice addition. In addition to the old moves, we'll also have ridiculous moves where bodies will be wrung in all sorts of ways (my favorite: kicking the back of the shins). And, of course, we'll bring back the fatalities but not the immensily unpopular animalities (thank God!).

Step 4: Aesthetics
Interesting stages will brought out well by nice graphics. Nothing on the level of Tekken 3 or Virtua Fighter 3, but nice looking. Sound will be the basic grunts, kupows, and bad music. Blood will be the selling point once again. It'll still spray from the fighters in pints, even when you just jab your opponent. The blood will fly on the floor but will seep through the concrete and out of the player's view.

Step 5: Overview
Basically, we'll have a "comeback" game. It won't be any good, but it will be better than Mortal Kombat 3, so people will call it a step in the right direction.

Overall: 5.0