The Enigma That Is Knuckles' Chaotix's Development

I was playing Knuckles’ Chaotix recently and… it’s not terrible. It’s not particularly good but there’s a lot to enjoy - the graphics, the soundtrack, the zone themes, the special stages are among the Sonic series’ absolute best, with some fantastic variety and creativity. Yet for all it has in those areas, it completely lacks in its level design, which, coupled with the unique yet unpolished tethering mechanic, make for a game that’s interesting in all aspects except its gameplay. It’s a very strange game.

It’s also very enigmatic when it comes to its development. I began to dig into what we know, and compared to the other Mega Drive / Genesis-era Sonic games, the development of Chaotix is still very much a mystery. We know the broad strokes: it started on the Genesis as Sonic Crackers, moved to the Saturn at some point, and then to the 32X, and became a spin-off featuring Knuckles and a bunch of other characters rather than Sonic and Tails.

But I want to go further. What do we know about this game, and what remains a mystery? So I spent a couple days pouring over Chaotix’s development and I’m presenting everything I’ve found here. I will clearly denote speculation on my part as speculation.

The Sonic CD Connections

I’ve seen it said that Chaotix was developed by the same team that developed Sonic CD - but is this really true? I’ve never seen a full breakdown of who worked on both and it struck me as just an assumption based on the fact that both are colorful Sonic games with weird gimmicks for add-ons that no one bought. So I decided to do a full credits comparison myself. And here it is!

• Naoto Ohshima, director of Sonic CD, is credited for original character concept in Chaotix. In a 2018 interview (contained in The Untold History of Japanese Game Developers: Volume 3), he confirmed his contributions were limited to designing Vector and Charmy.
• Takumi Miyake, who’s credited for landscape design and visual design in Sonic CD, is credited as chief graphic designer, attraction designer, original character concept, character designer, enemy designer, and boss designer in Chaotix.
• Kenichi Ono, who’s credited for game design in Sonic CD, is credited for game design and map design in Chaotix.
• Kazuyuki Hoshino, who’s credited for character design, special stage design, visual design, illustrations, and special stage sprite design in Sonic CD, is credited for original character concept, character design, and enemy design in Chaotix.
• Makoto Oshitani, who’s credited as producer in Sonic CD, is credited in the same role in Knuckles’ Chaotix.
• Masato Nishimura, who’s credited for landscape design and special thanks in Sonic CD, is credited for map design in Chaotix.
• Masumi Uchida, who got a special thanks in Sonic CD, is credited for attraction design in Chaotix.
• Tohru Watanuki, who got a special thanks in Sonic CD, is credited as an attraction designer in Chaotix.
• Shūji Takahashi, who got a special stage special thanks in Sonic CD, is credited as an object programmer in Chaotix.
• Yukifumi Makino, who’s credited as sound director, sound effect, and sound program in Sonic CD, got a special thanks in Chaotix.
• Jina Ishiwatari Tsukahara, who got a special thanks in Sonic CD, is credited for attraction design and character design in Chaotix.
• Yoshiaki Kashima, who got a special thanks in Sonic CD, is credited as a sound programmer in Chaotix.
• Yuichiro Yokoyama, one of Sonic CD’s game designers, got a special thanks in Chaotix.
• James Spahn, who got a special thanks in Sonic CD, also got a special thanks in Chaotix.
• Naofumi Hataya, who’s credited for “Cosmic Eternity [Believe in Yourself]”, BGM composer and arranger, and special thanks in Sonic CD, got a special thanks in Chaotix.

15 people worked on both Sonic CD and Knuckles’ Chaotix. While it’s definitely inaccurate to say both Sonic CD and Chaotix were developed by “the same team” - this is only a fraction of both games’ credits, and both were large projects for the time - there’s enough shared staff to establish a connection. A decent number of designers worked on both projects and it had the one of the same producers.

There’s other minor connections between CD and Chaotix beyond the development teams. Mosqui/Needlenose, the little mosquito Badnik from Palmtree Panic, pops up again in Speed Slider. Both feature levels with alliterative names. (“Palmtree Panic”, “Collision Chaos”, “Botanic Base”, “Marina Madness”, etc.) Both use the same jump sound effect, and no sound effect plays when you roll.

Perhaps the most interesting connection to me is in the Special Stage sprites. Since they’re played from a similar third-person perspective, I don’t think it should come as a surprise that Chaotix’s special stage sprites are based on Sonic’s from Sonic CD’s; if you look closely, you can see that the runcycles are more or less the same. But Mighty and Knuckles in particular have something interesting: their jump sprites are simple edits of Sonic’s from Sonic CD.

Spoiler: Images

(Mighty had his edge trimmed, but Sonic’s quills are still visible in the second frame. Meanwhile, Knuckles’ are nearly identical; the only differences are the different palette and removal of the ears.)

The Genesis Phase of Development

The narrative we’ve all heard is that Knuckles’ Chaotix was derived from Sonic Crackers, a prototype for the Genesis that was leaked by a Belgian hacking group in June 1995. (For those curious, the prototype leak is theorized to have originated from Clint Dyer, a Sega of America employee who wrote walkthroughs and is said to have sold prototypes that otherwise would’ve been tossed.) This is true, but it doesn’t tell the full story.

First, the name “Crackers”. It’s a name that makes no sense and undoubtedly has confused many over the years. It’s become more well known in recent years that “Crackers” is actually a simple mistranslation - the intended title is Sonic Clackers. The Japanese language doesn’t distinguish between L’s and R’s, so this is a fairly simple mistake. The name is actually significant because it might tell us where the inspiration for Chaotix’s most distinctive mechanic came from. Clackers are two balls connected by a string that make a “clacking” sound when they collide. Two balls connected by a string… hmm.

Spoiler: Images

Of course, it’s possible that someone noticed this similarity after the tethering mechanic was conceived, so we can’t say with confidence that Chaotix was inspired by a toy ball.

The ROM header also contains the name “Sonic Studium”, suggesting “Sonic Stadium” was another name Sega was considering for the game that became Chaotix. The “Stadium” title even made it into the Sonic Mars script, where it’s listed as an upcoming Genesis game from SoJ.

Spoiler: Image

What Clackers / Stadium contains is generally well known. It’s a fairly simple prototype featuring Sonic and Tails connected via the clacker-like tether running through two pretty simple levels, which are split up by top down “fields”. Although it’s obviously very, very early in development, it shows that a good chunk of Chaotix’s concepts had been conceived by this point. The tethering more or less works as it does in the final, though it’s not as polished. In addition, levels are already referred to as “attractions” and the day-and-night cycle is present. The levels that are present seem to be very early versions of Techno Tower and Speed Slider; in addition to the similar aesthetics, there’s some level design that appears to have made it into the final:

Spoiler: Images

Whether these two levels did end up becoming Techno Tower and Speed Slider still remains unconfirmed, though it’s been speculated for ages.

In addition, the ROM contains sprites for Sonic’s/Mighty’s wall jump, text referencing the Combi Catcher, and HUD graphics that ended up getting used in the Special Stages.

Ken Horowitz has theorized on Sega-16 that Clackers / Stadium was a submission ROM, which developers would present to management to demonstrate new concepts and seek approval. If Clackers was indeed a submission ROM, then it was certainly approved for further development, as evidenced by the fact it ended up coming out as Knuckles’ Chaotix.

One question: when did development on Clackers / Stadium begin, and how long did it last on the Genesis? The Clackers / Stadium prototype is dated April 1, 1994, on the title screen, but the ROM header contains a copyright date of July 1994. Fortunately, we have outside evidence that tells us which date is more accurate. A June 1994 prototype of Yuu Yuu Hakusho: Makyou Toitsusen contains leftover data from Clackers / Stadium: a load of Tails “field” sprites that aren’t anywhere to be found in the available build. Given that this build is dated before the header date, it indicates that the April date is, more likely than not, correct. It also indicates that Clackers / Stadium was still a Genesis game by June ‘94.

As for when development began, it’s tough to pinpoint a precise date, but Computer and Video Games wrote in its coverage of Chaotix at Winter CES 1995 that development began around January 1994. It seems that some of the Sonic CD developers who are credited in Chaotix (such as Nishimura and Hoshino) went directly from CD to Chaotix. Sonic CD was finished in August 1993, leaving an eight-month gap between the release of Sonic CD and the first build of what would become Chaotix. Past Sonic games seem to have taken a few months to progress from a concept to a playable build. For example, Sonic 2 entered development in January 1992, but the earliest prototype appears to be from around June, and Sonic CD’s earliest concept art is dated March 1992 when the earliest prototype is dated in December. So it’s possible that Clackers / Stadium was first outlined right as Sonic CD was finished, or sometime after. There’s no way of knowing, however, so we can only speculate.

Courtesy of the Sonic the Hedgehog 25th Anniversary Art Book, we do have some concept art from this phase of development. In the left image, I’d say the art in the bottom right corner is the only on that page we can definitively say was for Sonic Clackers / Chaotix. (Looks like there’s some writing on the concepts, so it’d be useful if those got translated.)

Spoiler: Images

And Masato Nishimura, one of the Sonic CD developers who went on to work on Chaotix, actually revealed some information about the prototype on Twitter in 2011! Here’s a machine translation of what he said - if anyone can give a better translation, please let me know and I’ll update this post:

The “Mr. Yajima” that Nishimura refers to is Toshiaki Yajima, who’s credited as chief programmer and 68K programmer in Chaotix. But “canceled due to SOA issues”? Hmm. This is something we’ll come back to later.

Got all that? Good. Things are about to get pretty murky from here on out.

The Saturn Phase of Development

This is where Knuckles’ Chaotix becomes very, very mysterious.

Did you know Chaotix was a Saturn game at one point? It’s a relatively obscure factoid. We don’t have any prototypes of it, and since there are few developer interviews regarding Chaotix, it’s not surprising that it’s slipped under the radar for so long. So how do we know there was a Saturn version? On May 2, 2014, our friend drx released a July 2011 phone interview he conducted with former Sega of America CEO Tom Kalinske. It includes this question and this response:

Drx added at the end of his forum post:

The existence of a Saturn build - or builds - of Chaotix is a good explanation for why there’s a large time gap (eight months!) between the two earliest prototypes (Stadium / Clackers and Chaotix 1207) that are publicly available. In that time, development easily could have moved from the Genesis onto the Saturn, and then from the Saturn to the 32X. It also seems to confirm that Chaotix was intended to be a mainline Sonic installment before it became a spin-off.

However, it’s a revelation that raises a lot of questions. Was the game always intended to be a Saturn game, even when the first prototypes were on the Genesis? (It wasn’t unheard of for game prototypes to be developed on lesser hardware rather than their intended platform - the first Kirby Super Star prototype was made for the Nintendo Entertainment System.) How long did this Saturn phase last? Which characters were in the game at this time?

As for a development timeline, Meat Miracle noted in the linked thread above that Sega had no working Saturn Silicons until May/June 1994 and the earliest library dates in Saturn development kits are from May 1994. The June 1994 Yuu Yuu Hakusho prototype indicates Clackers / Stadium was still on the Genesis in June 1994, and the earliest coverage of a 32X Sonic game (as we’ll discuss below) doesn’t appear until around October/November 1994. Which leaves a June/July to September/October window we know nothing about. The game could’ve been running on Saturn for as much as four months. But of course, unless we find a prototype or get more information, we won’t know.

It should be pointed out that Kalinske doesn’t paint the development in a particularly flattering light. He describes a project that was overly ambitious, behind schedule, overbudget - a nexus of all the things that can go wrong in game development.

The 32X Phase

Kalinske says that the Saturn Sonic game was cut into parts, with one part becoming the 32X game we know as Knuckles’ Chaotix (or simply Chaotix in Japan). The “split” could be the cancellation that Nishimura refers to. The 32X was largely a Sega of America operation, and the way Kalinske describes it, to me, suggests that the decision to cut down the game for a 32X release was one made by Sega of America.

Magazine articles about a Sonic-related project for the 32X started appearing in magazines cover-dated December 1994 and January 1995. (Based on my knowledge of cover dates, I’d assume this would place the news emerging around October/November 1994.) The earliest credible report appeared in the January 1995 issue of Electronic Gaming Monthly, which wrote in its “Gaming Gossip” column of a 32X Sonic game called “Sonic Chaotic” that’s been in development for over a year, planned for a June 1995 release, and being “programmed on Silicon Graphics workstations”. EGM claimed the game featured new cutting-edge technology and would star Sonic, Tails, Knuckles, and a “Red Sonic”. (I think this might be Mighty, but I have no idea.)

This isn’t the only source that mentions the name “Sonic Chaotic”. Remember that Clint Dyer fellow I mentioned a while back? At the end of his Sonic & Knuckles guide, he wrote these words:

The 1207 prototype of Knuckles’ Chaotix also features unused graphics spelling out “Sonic Crackers S32X”:

Spoiler: Image

So the 32X version was, for a time, still intended to feature Sonic - hell, it was still using the “Clackers” title going off these graphics. However, EGM was likely going off of some outdated information, as the same month, the Spanish magazine Super Juegos had a feature about a 32X Sonic spin-off called “Knuckles’ Ringstar”. This feature, found in issue #33, contains the earliest known screenshots of the game’s final form.

I can't include the screenshots because of forum limits. They're on TCRF.

The “Ringstar” title doesn’t appear to have stuck for long, especially since the prototypes we have from the era it was being referred to by this name use the final title. (Interestingly, early screenshots refer to Mighty as “Nat”, a change that’d be reverted by the 1207 prototype.)

Oddly, the developers seem to have been hesitant to label the game a Knuckles spin-off. The “FEATURING KNUCKLES THE ECHIDNA” text appears on the title screen in the 1227 prototype, but was changed to “FEATURING ESPIO THE CHAMELEON” in the 1229 prototype. Yet it was changed back to “FEATURING KNUCKLES” in the 0202 prototype.

Spoiler: Images

Knuckles’ Chaotix made its playable debut at Winter CES 1995, which took place from January 6 to 9, 1995. CVG’s preview, like EGM’s gossip column, emphasizes that the game was being developed using Silicon Graphics workstations. It’s a pretty blatant attempt to riff on Donkey Kong Country, a game that managed to sell nearly 10 million by hammering into your skull that the computers the developers used were the same ones Steven Spielberg used to make dinosaurs in Jurassic Park. I’m not sure if Chaotix was really developed using SGI workstations or if this is marketing bullshit (after all, Silicon Graphics was allied with Nintendo), or if it’s just an assumption the trades were making.

The developers continued to toil away as its final form began to take shape. We have 12 32X prototypes of Chaotix dated between early December 1994 and mid-February 1995, the earliest dated December 7, 1994 and the last dated February 16, 1995. After over a year of development, Chaotix was finally released in Japan on April 21, 1994 to a resounding "meh".

The Characters

I think it’s pretty well known at this point that Chaotix’s “new” characters weren’t new. Most, if not all, were drawn from pre-existing sources. We’ll go over those.

Vector was originally planned to appear in Sonic 1 as part of the “Sonic the Hedgehog Band” that would’ve appeared in the scrapped Sound Test. Time constraints forced the developers to remove the feature (including Vector) and they used the space the graphics took up in the ROM for the “Sega!” chant. Vector’s Chaotix design seems to blend his headphones from Sonic 1 concept art with an updated look used in unused sprites in SegaSonic Bros.

Spoiler: Images

Charmy originated in the Sonic the Hedgehog manga in 1992. This makes him the second Sonic character who originated in the manga before appearing in the games (the first being Amy).

Spoiler: Image

I previously mentioned this, but it’s been a while so I’ll mention it again. Ohshima revealed in 2018 that his sole contributions to Chaotix were to retrofit the existing Vector and Charmy designs for the game.

Espio is said to be the only original Chaotix member, created by Takumi Miyake. But was he? Azookara proposed a fascinating theory earlier this year: Espio was based on a prototype of Knuckles or was a separate pitch for the rival in Sonic 3 that ended up being recycled in Chaotix. Sources claim Knuckles was originally a dinosaur/reptilian (Espio may be called a chameleon, but he also strongly resembles a triceratops), had a whirlwind move, and walked on walls and ceilings instead of climbing - all qualities that describe Espio.

Then Bomb was based on the Sonic 1 Badnik, and Heavy is new. No one really cares about him though, so we’ll skip trying to understand his origins.

As evidenced by the fact Sonic and Tails take up the first two slots, the level select screen apparently tells us the order that characters were added in. Sonic and Tails were the first two characters. Sonic obviously became Mighty, their sprite sheets being nearly identical.

Tails was dummied out sometime before the 1207 build, though his palette was still in use in 1207 and his behavior remained intact until 0119. As most know, Tails’ remnants can still be controlled in the final game by selecting the character “**********” from the level select.

I can't include images for Sonic and Tails because of limits. They're both on the wiki.

Knuckles is in the third slot - indicating he was added sometime after Sonic and Tails. (While he’s not in the available Clackers / Stadium prototype, his palette is.) Interestingly, while his idle, jumping, and running sprites are clearly based on his Sonic 3 sprites, his gliding, climbing, and skidding sprites, which originate in Sonic & Knuckles, are different.

Spoiler: Image

This suggests to me that Knuckles was added before Sonic & Knuckles came out and the Chaotix team made new sprites because didn’t have access to those sprites. (The other sprites are seen in Sonic 3 in the zone transition cutscenes.) Not to mention, in the 1207 prototype, climbing has completely different sprites and works differently from Sonic & Knuckles and the final Chaotix: you have to hold jump the entire time while climbing, or else you’ll fall. But again - this is speculation.

Charmy and Vector are the next characters, so they must’ve been added after Knuckles. There’s also strong evidence they were added when the game was still on the Genesis. Firstly, the 1207 prototype contains different, less colorful running Vector sprites - likely a remnant of having to work within the Genesis’ palette limitations.

Spoiler: Images

Perhaps more revealing are these unused monitor graphics designed to be rendered by the Genesis. Charmy and Vector are there, alongside Sonic, Tails, and Knuckles.

Spoiler: Image

Charmy’s behavior seems to have been pretty much finalized by 1207, though Vector’s airdash didn’t come until later. Regardless, there’s enough evidence to show that Charmy and Vector were in the game early on, back when it was on the Genesis.

Next come Bomb and Heavy. They also appear to have been in the game when it was on the Genesis, since monitor icons for them appear alongside Sonic, Tails, Knuckles, Charmy, and Vector. Though it looks like their designs were altered - Bomb originally looked like a Sonic 1/Sonic CD Bomb enemy, while Heavy resembled a weight.

Espio is the last character listed and unsurprisingly appears to have been the last character worked on. He doesn’t appear alongside Vector and Charmy in the monitor icons, and while he’s present as far back as 1207, his abilities weren’t even implemented until the 0111 prototype. Interesting for a character who was once considered to be the star of the game.

Wild Speculation on My Part That Is Probably Wrong

I need to label this “wild speculation” because I could be totally talking out of my ass here. Like, I could be wildly stupid and wrong for suggesting this. But. I just want to include it as some food for though.

Spoiler: seriously this is probably wrong don't make fun of me please

Kalinske says the game was so big that it was split into parts. Yet we only know one of the “parts”, the 32X game Knuckles’ Chaotix. What are the other “parts” he’s talking about? Are there other canceled Saturn/32X Sonic games that were split from the project that became Chaotix?

We do know that Clackers / Stadium had two parts, the side-scrolling “attractions” that made it into the final game, and the top-head “fields” that didn’t. We know these were still in the game in June ‘94. There are unused jumping sprites, and the Tails sprites in Yuu Yuu Hakusho show you could spin dash and run like normal - as if the fields were meant for platforming. For those who hate speculation, this is where the crazy speculation begins. But hear me out.

Isometric fields.

Platforming in these isometric fields.

Running, jumping, and spindashing in these isometric fields.

Did this concept become…

Spoiler: Images

… Sonic 3D Blast?

I know, this is a ridiculous idea, which is why I must emphasize that it’s pure, unfiltered speculation. But I wanted to throw it out there because the similarities are striking to me.

The game was split into “parts”, per Kalinske. Did Sega think the isometric sections were strong enough to become their own game? And then commissioned Travellers’ Tales to develop the concept into a full game? I think it’s very well possible.

In Conclusion

Knuckles’ Chaotix is a weird as shit game that was a clusterfuck behind the scenes and I wasted a full week trying to piece together every little detail we know about it for the fuckin’ hell of it. God I have no life