The Super Nintendo version of the original Mortal Kombat was technically superior to the Sega Genesis one. However, the play control was off and, as we all know, it was missing the blood and some fatalities. These two factors caused the Genesis version to hugely outsell the Super Nintendo one. This was remedied with the release of MK2. The Super Nintendo version was better than the Genesis one in every measurable way. Nintendo conceded and allowed all the gore to be included as well. The result was the Super Nintendo version of MK2 being the clear winner among 16-bit platforms, both in quality and in sales.
Play control:
The play control is very close to the arcade, the differences are hard to notice. The timing of some combos are slightly different but nothing major. I found that Kintaro and Shao Khan are easier to beat in this version than the original as well.
Graphics:
The characters and animation look great on this version.
Sound:
Very solid port of the soundtrack to the Super Nintendo.
Extras:
This version has one of the coolest features of any fighting game, an 8-man elimination match (also called "tournament mode"). I guess this is kinda ripped off from King of Fighters but whatever. I spent hours playing friends in this mode, it was even more fun than playing at the arcade. In addition to that it has adjustable difficultly, configurable controllers, and a host of cheat codes.