Knuckles Chaotix (simply known as Chaotix in Japan) is an action-platform game in the popular Sonic the Hedgehog franchise, released for the Sega 32X in 1995, and the only Sonic game to appear on that system.
According to the Japanese instruction manual, Dr. Eggman discovers a mysterious island containing artifacts known as Chaos Rings - magic rings infused with Chaos Emerald energy - and built his base (dubbed the Newtrogic High Zone) there. Mighty the Armadillo, Espio the Chameleon, Charmy Bee, and Vector the Crocodile, all arrived at around the same time, but were captured by Eggman and placed in his "combi catcher" machine to avoid interfering with his plans. Knuckles, curious about the island, ventures there as well to find out more about the Chaos Rings.
The game is played with two characters, joined together by an elastic ring (with the cord shown as a trail of sparkles). Before each stage, you use the combi catcher to randomly select your partner, and then select a stage (also at random; how fast the stage select indicator moves depends on what day cycle you're currently on), progressing through it in normal Sonic fashion, defeating Eggman's robots and reaching the giant ring at the end of the stage. A great deal of cooperation is required to make it through the game, as you have to make use of the properties of the elastic rings you and your partner hold in order to zoom and slingshot your way past obstacles.
- Bottomless Pits: Averted during the normal stages. Since there are almost always two characters on the field at one time, stages are deliberately designed to keep this from happening. The Special Stages, however, are prone to this.
- Bulletproof Furry Shield: Partners can be used for this purpose, as they only lose one ring when hit instead of all of them (unless your partner is Bomb, who explodes when hit, causing you to lose all of your rings if you're within its blast radius).
- Canon Discontinuity: Word of God says that the Chaotix were re-imagined for Sonic Heroes, not re-appearing. Also referenced in Sonic Generations, which has Mighty's last appearance at 1993.
- Canon Immigrant: Espio made his debut here before making appearances in other media. Mighty the Armadillo is a Canon Emigrant, having first appeared in Sega Sonic the Hedgehog.
- Cap: The game has a cap of 255 rings instead of 999. Then any other rings collected are turned into points.
- There is a cap the other way as well. You can get as low as -99 rings. Anything below that and you are sent back to the attractions screen. You lose rings by calling your partner.
- You are sent back to the attractions screen if hit with anything under 0 rings.
- Also, you can only take 200 rings into a Special Stage. Anything above that is simply lost.
- Captain Ersatz: Mighty the Armadillo is literally just an edited Sonic sprite. Which makes the appearance of Sonic in the ending pretty strange.
- Circus of Fear: The "Speed Slider" level. It's more like a cheery roller coaster, but Creepy Circus Music plays during the merry-go-round boss battle.
- Comic Book Adaptation: In both Archie comic (as a 48-page special) and Sonic the Comic (as a five-part serial).
- And the characters became regulars for a long while, in comparison to the many years before their next appearance.
- Credits Medley: The only non-main line Sonic game with one.
- Dummied Out: Tails. Also, sprites of him in the Tornado, and Super Sonic have been found within the ROM.
- Easter Egg: Amy in the sound test menu.
- Eternal Engine: The "Techno Tower" level.
- Fan Nickname: "Wechnia", for the Dummied Out character called "**********" by the game, because he appears as a glitched, white Knuckles. Research on the game's prototypes eventually revealed he actually was Tails.
- Flight: Instead of spin-dashing, Charmy does this to get around. It is a complete and utter Game Breaker, since he has no "cooldown" period.
- However, Charmy can't jump in the traditional sense, so he takes a bit of getting used to. But yes. If you want a ridiculously easy game experience, wait until you get to Techno Tower, which can be done in less than a minute with Charmy.
- Giant Space Flea From Nowhere: At the end, Robotnik and Metal Sonic are defeated and fly off together into the background... and a gigantic snarling red demonic Metal Sonic suddenly rises into the screen and proceeds to try to smash and blast you into paste.
- Golden Ending: Accessible only if you've collected all of the Chaos Rings. If you miss one, you get the bad ending where Eggman's giant robot destroys the island.
- Idle Animation: Every character has one...
- Easter Egg: ...And if you leave them idle for a minute, Metal Sonic shows up and shoots at you.
- In-Universe Game Clock: The game has a Day and Night system that changes as you enter and leave each level.
- Joke Character: Heavy and Bomb.
- Lethal Joke Character: Heavy the Mechanic is completely indestructible. In fact, he can open monitors and destroy enemies just by walking into them. You could pretty much pick him up and run around with reckless abandon while holding him in front of you, barely suffering any damage. Taken into better effect if you break a monitor that's showing him, or -- more permanently -- select him as your player character through the debug menu.
- Loads and Loads of Characters: For a Sonic-based platformer of it's time. To be specific, Sonic the Hedgehog had only 2 characters. Sonic the Hedgehog 2 had 3, and Sonic 3 and Knuckles had 4 characters. Sonic CD had 3. Knuckles' Chaotix has 6.
- Mighty Glacier: Heavy. He's incredibly slow, but invincible.
- Noob Cave: The "Isolated Island" level. There are no enemies or traps, and it's basically you and your partner running wild until you reach the goal.
- Spiritual Successor: The game's levels, songs and general style have a Sonic CD feel to them. A couple graphics and sounds from that game are also reused here. On the subject of reused badniks, Pata-Bata and Mosqui from Palmtree Panic appear in Speed Slider. Also, both games feature Metal Sonic as The Dragon, and here he even takes over Sonic's place for the Idle Animation Easter Egg.
- Teamwork Puzzle Game: The whole elastic-ring thing.
- Wall Jump: Mighty and Espio.
- 4 if you count Silver Sonic
- 6 if counting Mecha Sonic and EggRobo, and 19 if you count all the sub-bosses
- 4 in the Updated Rerelease, making 5 if counting Metal Sonic
- 9 if counting Metal Sonic, Heavy and Bomb, and also making 11 if counting Sonic and Tails at the Good Ending