Long-time gamers might be familiar with one under-utilized piece of technology from the 1990s: lock-on technology. This was Sega's buzzword that allowed the Genesis (or MegaDrive) cart Sonic & Knuckles to physically connect to other cartridges to enhance gameplay. Up until recently, it was thought that this was only compatible with two existing games: Sonic the Hedgehog 2 and Sonic the Hedgehog 3, allowing the gamer to play as Knuckles in those games. This was until 2005, when a user-created patch added the ability to play as Knuckles in the original Sonic The Hedgehog (full story).

Today, a former programmer at Probe (who has chosen to remain anonymous) released the code showing Knuckles was scheduled to be a playable character in the original Mortal Kombat. Some of the details on the cooperation between Sega and Probe are still somewhat murky, but it is apparent that the gameplay was 100% finalized. We tested it on the original hardware, and all of the special moves were intact. Knuckles even has a Fatality. Check out the pics below:

It is unclear why the code, which appears to be finished, had to be pulled from the game. Perhaps it was due to concerns about the violence, or maybe Nintendo was upset about Sega getting such an exclusive.

Update: It's been confirmed. A spokesman from Sega of America, speaking on condition of anonymity, stated that it was important for Sonic & Knuckles be released with a rating of E for Everyone. That meant that all traces of the Fatality, or any connection to the Mortal Kombat franchise, had to be removed.