Mortal Kombat Nitro Developer Remembers the Faster, Bloodier SNES Version That Never Was

From its debut in 1992 through April 1995, the Mortal Kombat franchise generated over $1 billion in revenue between coin-op machines and cartridges for home systems. That figure accounts for the first two games; their sequels earned billions more. At a moment’s notice, hardcore fans and collectors can scour Amazon, eBay, and Craigslist for any of those versions and browse page after page of listings, giving them plenty of time to find the best deal on MK games and merchandise.

Mortal Kombat Nitro will never appear in those listings. Only two copies exist, and their owners have no plans to part with them.

Over the winter and spring of 1993, Sculptured Software and Acclaim struggled to meet Nintendo’s stringent demands for a sanitized version of Mortal Kombat on Super NES. By release, blood had been changed to sweat, and tamer finishing moves had replaced their grisly arcade counterparts. Early on, however, the Super NES port looked markedly different.

“There were versions from Sculptured that had blood,” says Rob Holmes.

Jeff Peters was the project manager at Sculptured Software charged with leading a small team in converting the arcade game to the 16-bit console. While he understood Nintendo looking out for its family-friendly reputation, he thought MK’s violence wasn’t worth all the fuss.

“The blood and guts were so over the top that they were cartoonish,” says Peters.

While Sculptured Software’s engineers translated the arcade version’s code to the Super Nintendo and their artists processed characters and arenas, Peters spent much of his time on the phone. He would show the latest builds to managers at Acclaim, who sent them to Nintendo for approval. Nintendo would get back to Acclaim, and Acclaim would pass their feedback to Peters, who shared it with the team. Unsurprisingly, most approvals failed to meet Nintendo’s standards. What frustrated Peters was that Nintendo provided little guidance. “As we got the game up and running, we would have to test the fence. Is this blood toned down enough? No? Okay, is this toned down enough?”

After several rounds of back-and-forth, Peters gave Nintendo what they wanted. “We’d say, ‘What if it’s sweat flying off? We’d just make the blood translucent.’ And Nintendo was like, ‘Oh. Yeah.’”

“If you think about it,” says Holmes, “the blood is still there. It’s just gray sweat, or fairy dust, or whatever you want to call it.”

The blood and guts were so over the top that they were cartoonish


Gray blood, jokingly called sweat by the developers, was deemed permissible so long as gobs of the stuff didn’t splatter over the ground the way it did in the arcade. Sculptured reworked the sweat so it sprayed into the air and then dissipated. Nintendo also established a guideline for fatalities.

“They turned around to us and said, ‘Okay, no blood, and no decapitation,’” says James Fink, product tester at Acclaim.

Banning decapitations meant new fatalities for Sub-Zero, Johnny Cage, and Raiden. Fink and the team at Sculptured brainstormed ideas for new finishers. They had no time to make new graphics. That meant recycling animation frames. Instead of blasting his opponent’s head off with a bolt of lightning, Raiden pumps electricity into them until their skeleton disintegrates into a pile of ash with the skull resting on top. To replace Sub-Zero’s iconic spine rip, the developers created a sequence where the ninja freezes opponents and shatters into chunks of ice.

“It was more of an insult to the defeated player when you do that stupid backhand move and shatter them,” says Fink, who was annoyed at Nintendo’s insistence on watering down content.

Before Nintendo insisted on removing blood and sanitizing fatalities, the team at Sculptured had thought up a revised finisher for Johnny Cage that was arguably better than the one Midway had given him. Rather than punching his opponent’s head off their shoulders, he kicks them through their chest hard enough to send blood, bones, and their liver—”that’s what some blobs looked like,” Peters says of the gore—exploding out of their backs. “It’s a good example of what a fatality was before it had to go through Nintendo’s sanitizing machine.”

Nintendo rejected the finisher. Developers at Sculptured and Acclaim threw up their hands — Nintendo had only said no decapitations — but did what was expected and removed the gore. In the final version, Cage kicks his foot through his opponent’s chest and watches as they squirm at the end of his leg. Same animations, squeaky-clean results.

After uploading the latest build for Acclaim — which took forever to send over modem — Acclaim called Peters to report that Nintendo had rejected the game again. “They came back to us like a half-hour later said, ‘Oh, by the way, we need you to take out Kano’s heart fatality,’” Fink says.

That posed a problem for Sculptured and Acclaim. “We didn’t have time to create a new fatality, or we wouldn’t have met the deadline for Mortal Monday,” Fink says. In the final product, Kano tears something out of his opponent’s chest, but what that something is, is open to interpretation. According to Fink, it’s a heart that Sculptured’s artists painted gray. Nintendo gave their consent, and the game was ready for manufacturing.

As frustrating as they found jumping through Nintendo’s hoops, Acclaim and Sculptured Software knew they had no choice but to comply. “They could fail your game if they didn’t like what was in it,” Peters says.

No one at Sculptured or Acclaim was surprised when the Genesis version outsold the Super Nintendo port nearly five to one. But there was another, less publicized reason players preferred Mortal Kombat on Sega’s platform.

Sculptured’s port went through hell during its short span of time in development. Early on, one programmer claimed he could code a one-to-one conversion of the arcade game with no help. Months passed before it became obvious he was in over his head. Now even more pressed for time, Peters put three programmers on the project. Along the way, the code responsible for handling player input and referencing which animations to call got mangled. The result was a control scheme that was borderline unresponsive. When you tap up to jump, your character stands there as if no button was pressed. You have to press hard or hold buttons down for the game to acknowledge them.

I said, ‘Listen, I’ve got this idea. Street Fighter II got Street Fighter II Turbo. Let’s make Mortal Kombat Nitro.’


Fink ground his teeth every time he read a review criticizing the Super NES’s port’s controls. He wasn’t angry with them for knocking his favorite game. He was angry because he knew they were right.

“It didn’t play like that originally,” he says. “It actually played, in all honesty, closer to the arcade than the Genesis version.”

What really bothered Fink was that the Super Nintendo’s graphics were much closer to the arcade than Sega’s. If not for Nintendo’s restrictions and the port’s flawed code, the Super NES would have hosted the best port, no contest.

Fink took this complaint to Rob Holmes and suggested a way to make things right. “I said, ‘Listen, I’ve got this idea. Street Fighter II got Street Fighter II Turbo. Let’s make Mortal Kombat Nitro.’”

Holmes liked the idea, and he thought Nintendo would like it, too. Mortal Kombat was selling so well on Genesis that Nintendo was slowly losing ground they had gained by securing exclusive rights to the first home adaptation of Street Fighter II. Nintendo had already relented and informed Acclaim they would allow blood in ports of the next Mortal Kombat. An updated version of MK with all the blood and the original fatalities would delight fans, which would please Nintendo.

Fink corrected him. He wasn’t proposing a clone of the arcade game. That was just a starting point. He envisioned more blood, more fatalities, more costumes, and tons of new features. Holmes told him to document his ideas. Ecstatic, Fink returned got to work on his design pitch. “At the time as a 21-year-old kid, I wasn’t the CEO of a company, but that I got green-lit on this, I was like, ‘All right, finally, I can make the game the way it should be.’”

Outlining Mortal Kombat Nitro was easy. Street Fighter II’s first upgrade, Champion Edition, had added the previously unplayable boss characters to the roster. Nitro would do the same by making Goro and Shang Tsung playable. Reptile would join the lineup, too, and he’d possess all of Scorpion’s and Sub-Zero’s special moves and move twice as fast, just as he did when under the AI’s control. Fink understood the appeal of secret characters—players were still dissecting the arcade and home versions to uncover anything else Ed Boon and John Tobias may have hidden away—so he knew he couldn’t make Reptile playable without adding a new hidden character to replace him. His suggestion was the original Kung Lao, Liu Kang’s ancestor, who had defeated Shang Tsung 500 years earlier only to be slain by Goro, who became the reigning champion.

The biggest change would be players’ ability to take their character down light or dark paths in the tournament. If you choose a “good” character such as Sonya or Liu Kang, and only kill “bad” characters such as Kano, you’ll unlock a new costume reflecting your alignment. Kill other good characters, and you’ll turn evil.

“So, for example, Sonya is given the opportunity to kill good characters, but if she does, she gets a bad ending. But if she just kills Kano, who was her target, you’d get the good ending,” Fink says.

Acclaim approached Midway with Fink’s design for Mortal Kombat Nitro. Releasing an upgrade was doable on a technical level: Sculptured had archived versions with blood instead of sweat, and they could reinstate fatality animations such as Johnny Cage’s gorier chest kick. Fink had an artist draft sketches showing characters in new outfits based on good and evil alignments: a blood-red scorpion, Cage wearing golden pants. Before long, Sculptured Software had a prototype where players could choose Reptile or the two bosses. It was glitchy, but it was playable.

Before Nitro progressed further, Midway told Acclaim and Sculptured Software to halt development. The notion of anyone creating a sequel or upgrade to their game was a nonstarter for Boon and Tobias. Acclaim’s bosses backed down without a fight. It was early 1994, and Mortal Kombat II was bringing in millions of dollars in quarters; soon, it would be time for Acclaim, Sculptured Software, and Probe to tackle conversions.

“They were afraid that by the time MK Nitro came out, the sales would interfere with MKII,” Fink says.

Fink disagreed. Casual players would buy home versions, but as a diehard arcade rat, he believed hardcore MKII fans would stick to the arcade’s superior hardware regardless of a home port’s availability. Bob Picunko, who had spearheaded Mortal Monday’s campaign and was already wading through the early stages of MKII’s marketing campaign, saw things differently. Sculptured had worked until their deadline on the first MK. Assuming MKII’s Super NES conversion was just as stressful, they would need to devote every spare minute to coding, debugging, and approvals.

“The issue was, could we really compromise Mortal Kombat II by taking the development team to make a half-step version of the first game?” Picunko says. “Also, would a consumer who bought MK1 buy Nitro, plus another game coming out right after it?”

Both perspectives had merit. The most devoted MK fans who only had a Super Nintendo and were disappointed with their toned-down experience probably would have leaped at the chance to buy a better version. After all, the most impassioned Street Fighter II players dropped cash on every update. However, sales history showed that most consumers weren’t thrilled at paying another $60 to $80 for new versions.

When Capcom’s fiscal year ended in March 1993, it had sold 6.5 million copies of SFII for Nintendo’s 16-bit machine, the first appearance of the game at home, and Capcom’s most successful single-platform release of all time as of 2022. Street Fighter II Turbo for Super Nintendo added more characters, more special moves, and speedier fighting, but topped out at 4.1 million. Super Street Fighter II, the franchise’s last release on Super Nintendo, only sold two million. On Sega Genesis, Street Fighter II: Special Champion Edition—the equivalent of SFII Turbo—came in last at 1.65 million.

The numbers told the story. Some MK fans would add Nitro to their collection, but not enough to risk affecting Mortal Kombat II.

“To this day, I believe Mortal Kombat II on Super Nintendo is the best home version of that game,” Picunko says. “That game probably would not have been as good if the developers would have had to work on an in-between version.”

Fink still believes in Nitro’s design and owns one of two chips containing Nitro’s code. His copy has blood, Kano’s original heart-rip fatality, and Cage’s chest kick complete with blood and guts. Years later, he gave the other ROM chip, which contained more playable characters, to a friend from Midway. “I still have one, which is very wonky, and one that I gave to Ed Boon,” Fink says. “He might have lost it by now. Who knows? This was almost 30 years ago.”

This excerpt is from Long Live Mortal Kombat: Round 1. Written by David L. Craddock, it goes behind the scenes to reveal untold stories from the franchise’s arcade era. The book will be released on October 8, and is available for pre-order on Amazon and from the publisher.