Sonic races through the green fields. The sun races through a blue sky filled with white clouds. The ways of his heart are much like the sun. Sonic runs and rests; the sun rises and sets. Don't give up on the sun. Don't make the sun laugh at you.Sega
— Words taken from Japanese cover of Sonic & Knuckles.
's third 16-bit
entry in the Sonic the Hedgehog
series, and the followup to the wildly popular Sonic the Hedgehog 2
, was so epic that time and hardware constraints forced them to split it into two separate games
:Sonic the Hedgehog 3
, released on February 2, 1994, covered the first half of the game, with gameplay as Sonic, Tails, or both. Knuckles the Echidna, the final member of Sonic and Tails' Power Trio
, made his debut in this game, but as an antagonist rather than a playable character.Sonic & Knuckles
, released on October 17 of that same year, covered the second half of the game, including Knuckles' Heel-Face Turn
, and allowed gameplay as either title character (but not Tails).
The game also featured "Lock-on Technology", a slot on top of the cartridge in which another Mega Drive / Genesis cartridge could be inserted. By connecting the Sonic 3
and Sonic & Knuckles
cartridges this way, the two could be played as one complete story, Sonic 3 & Knuckles
, with all three characters playable for the entirety, as was originally intended.
When playing as Sonic or Tails, the plot picks up right where the Genesis Sonic 2
left off. Dr. Ivo "Eggman" Robotnik's Death Egg, just recently destroyed by Sonic, crash lands on the mysterious Angel Island (or Floating Island, as the American game manuals called it). Sonic and Tails follow, intending to stop Robotnik from rebuilding the Death Egg. Not one minute after landing, Sonic gets a face full of fist, courtesy of the island's native inhabitant: Knuckles, the last surviving Echidna and protector of the Master Emerald whose power keeps Angel Island aloft. Knuckles is convinced that Sonic is a thief who intends to steal said Emerald. Why? Because Robotnik told him
So while Sonic and Tails thwart Robotnik, Knuckles waylays them with traps and all around acts as a thorn in their side. This finally comes to a head when everyone reaches the Hidden Palace: Robotnik steals the Master Emerald and electrocutes Knuckles for trying to stop him. Knuckles realizes he's been had, and immediately joins Team Sonic
, showing them how to get out of the Hidden Palace and onto the Death Egg.
The plot of Knuckles' game covers most of the same levels as Sonic's, and features Knuckles fighting one of Robotnik's EggRobos (rather than the Doc himself) piloting souped-up versions of the level bosses. This culminates with a battle in the clouds against a Master Emerald-powered Mecha Sonic. It's a bit unclear when
this all occurs in relation to the plot of Sonic's game. Official sources, such as the game manuals, imply that both plots occur simultaneously. However, in-game details appear to contradict this
, and suggest that Knuckles' plot begins shortly after the end of Sonic's plot.
The gameplay represented further Sequel Escalation
compared to Sonic 2
: The top speeds were even faster, the levels were even larger, and for the first time every
Act featured a boss fight.note
There was more focus on plot as well—Knuckles' antagonism towards Sonic and Tails was shown through a number of in-level, wordless cut scenes, and every level ends with a brief scene of the characters traveling to the next level (the second act of each zone typically started exactly
where the first act ended, with the player simply regaining control after the end-of-level sequence).
A number of game mechanics made their Sonic
debut here as well, such as a game save feature and specialized shields. The Special Stages from Sonic 2
, where the Chaos Emeralds could be won, were revamped, and three different Bonus Stages were introduced, where extra rings and powerups could be collected. Cast Speciation
(first introduced in the previous year's 8-bit title Sonic Chaos
) was further developed: Sonic could make use of a brief, midair "Insta-Shield", and do a special attack while having one of the shields (a double-jump with the lightning shield, a bounce attack with the bubble shield, a fiery charge attack with the fire shield); Tails could fly (by himself or while carrying Sonic) and swim; and Knuckles could glide and climb sheer walls, but couldn't run as fast or jump as high as Sonic.Sonic & Knuckles
' lock-on technology also worked with the Sonic the Hedgehog 2
cartridge, allowing you to play Knuckles in Sonic 2
. The developers attempted to implement a similar feature with the original Sonic the Hedgehog
, but found that Knuckles' color palette was incompatible with the game's
(though a fan hack
eventually proved that Knuckles could indeed be implemented in Sonic 1
, by using two shades of red on his sprite as opposed to four or five). Instead, combining the two cartridges (or the 1997 compilation cart Sonic Classics
) gives you the Blue Sphere
minigame, with over 100 million
variations on the Special Stage.
Oddly enough for a franchise at its peak, this would be the last core series Sonic
game until Sonic Adventure
, which directly follows this one. Sonic the Hedgehog 4
is a proper sequel, though the Excuse Plot
of Episode I
doesn't suggest it.
Provides examples of:
- Action Bomb: Iwamodoki.
- Advancing Boss of Doom / Advancing Wall of Doom / Descending Ceiling / Auto-Scrolling Level / Get Back Here Boss / Rise to the Challenge: There's a higher concentration of "keep moving or die!" scenes here than in any other Sonic game.
- The auto scrolling scene with the bomber airship in Angel Island Zone Act 2.
- The wall of doom in Hydrocity Zone Act 2.
- The altering landscape in Marble Garden Zone Act 2.
- The rising water level in Knuckles' version of Launch Base Zone Act 2.
- The auto scrolling boss fight in Mushroom Hill Zone Act 2.
- The crumbling airship in Flying Battery Zone Act 2.
- The rising sand sequences in Sandopolis Zone Act 2. The boss of the level is an advancing sphinx-mecha, which crushes you against a wall if you take too long to defeat it.
- The pre-boss fight forced-scrolling scene in Lava Reef Zone Act 2.
- Robotnik's screen-filling, inexorably advancing mecha in Death Egg Zone Act 2. After defeating it, you chase Robotnik's Eggmobile, carrying the Master Emerald, while the platform collapses behind you.
- The entirety of The Doomsday Zone.
- One of the three Bonus Stages features this, with a glowing, upward-climbing double helix that ends the level if you touch it.
- Airborne Aircraft Carrier: Flying Battery Zone; the Flying Battery also tries to bomb Sonic in Angel Island Zone.
- Airborne Mook: Caterkiller, Jr., Buggernaut, Jawz, Bubbles, Batbot, Star Pointer, Flybot767, Orbinaut, Butterdroid, Dragonfly, Hyudoro, Fireworm, Eggrobo, Spikebonker, and Chainspike.
- Always over the Shoulder: The bonus stages.
- Amusement Park of Doom: Carnival Night Zone. Also, Balloon Park from the 2-player mode.
- This is very literal in the minds of many when you consider the barrel.
- Ancient Egypt: Sandopolis Zone is Ancient Egypt on the Floating Island.
- And I Must Scream: Subverted: when you beat the Lava Reef Zone boss, Robotnik sinks into the lava, which cools and hardens seconds later, seemingly trapping him inside. After the Knuckles fight in Hidden Palace Zone though, he's shown to be perfectly fine.
- Another Side, Another Story: ...Maybe. It's hard to tell, given the minimalist style of 16-bit era storytelling, but Knuckles' adventure might actually take place after Sonic's; see here for an analysis.
- Artistic License – Physics: Granted, the game was never meant to be physically realistic, but one notable point is that the second phase of the Doomsday Zone's boss implies the presence of drag in space, given that the ship shoots bombs forward, that then slow down and fall behind.
- Attack Drone: As Super Tails, the golden Flickies that follow him serves as such, immediately attacking any enemy or boss that's on-screen.
- Badass: Mostly Knuckles but Sonic fits to the category too.
- Background Boss: The first part of the final boss.
- Bag of Spilling: The good ending of Sonic 2 is used as the canon one, with the opening cutscene showing Super Sonic briefly before Knuckles punches the emeralds out of him and takes them away.
- Bait-and-Switch Boss: Knuckles's version of Sky Sanctuary opens with EggRobo attacking... but then Mecha Sonic shows up and (unintentionally) destroys it, and you fight the Evil Knockoff of Sonic instead.
- Batman Can Breathe in Space: Death Egg Zone Act 2, and The Doomsday Zone.
- Because Destiny Says So: The mosaics in the background of Hidden Palace Zone are clearly a stylized depiction of Hyper Sonic's fight with the final boss in Doomsday Zone.
- Bedsheet Ghost: In Sandopolis Zone Act 2.
- Berserk Button: The second stage of the Death Egg Zone's miniboss seems to have one: it will start spinning a pair of spiked platforms extremely rapidly while firing off a massive laser beam if you attack it.
- Big Boo's Haunt: Sandopolis Zone Act 2; the ghosts will pester you (eventually hurting you) constantly if you don't keep the lights on.
- Blackout Basement: Carnival Night Zone Act 2 (for Sonic and Tails), and Sandopolis Zone Act 2 without the outside lighting.
- Bonus Stage: Unique among Sonic games for having two types:
- "Special Stages:" A 3D maze where you must "Get Blue Spheres". Finishing earns you a Chaos Emerald. Accessible via giant rings hidden in the levels.
- "Bonus Stages:" Stages for collecting rings and powerups. Accessible via a circle of stars that appear if you pass a star post with 20 or more rings. There are three types:
- A giant gumball machine that Sonic can turn by bouncing back and forth on platforms. Each gumball represents different power-up items (rings, shields, extra lives, etc).
- A 360-rotating area that is a Genre Throwback to the Sonic 1 special stages except with a Casino Night-esque slot machine in the center of the stage instead of a chaos emerald.
- A pinball-type arena with a glowing, upward-climbing double helix at the bottom that continuously rises upward. This is the only of the three stages that the player can "beat" by reaching the top of the stage before the helix.
- Book Ends: The game begins with Sonic flying towards Angel Island by plane and ends with him leaving. By collecting all Emeralds, Sonic also brings the Master Emerald back to Knuckles, who had taken the Chaos Emeralds from him in the beginning.
- Boring but Practical: Sonic's insta shield looks pretty underwhelming compared to Tails and Knuckles abilities, which allow far more expansive exploration and easter egg locating, however when mastered, it's split second invincibility can make obstacles and bosses a breeze.
- Boss-Only Level: The Doomsday Zone. Technically applies to the Death Egg and Lava Reef bosses as well, if only by programming. Knuckles' version of Sky Sanctuary also qualifies, as it consists of his last two bosses and no platforming whatsoever.
- Boss Rush: Sky Sanctuary Zone is a rehash of bosses from previous games.
- Bottomless Pit Rescue Service: With the Marble Garden Zone boss, due to the nature of the battle.
- Brick Joke: As you run through Launch Base Zone Act 1, you'll eventually find Dr. Robotnik carrying some sort of box around. That's the stage's midboss. When you defeat it, you might notice there are another two boxes in the wall. Those are the ones Knuckles will later fight in his version of the level.
- Build Like an Egyptian: Sandopolis Zone Act 2.
- But Thou Must: There's no way around freeing the ghosts in Sandopolis; you have to free them in order to advance.
- Cast Speciation
- Chekhov's Gun: The breakable objects that Knuckles could...er, break through to reveal alternate paths through the levels were this in the original Sonic 3, as the player could clearly see pathways behind some of them, but had no way to get there until Sonic and Knuckles was released.
- Circling Birdies: Happens to Knuckles after Eggman shocks him in Sonic's version of Hidden Palace Zone.
- Comic Book Adaptation: In both Sonic comics:
- The Archie comic had a short adaptation of Sonic 3 in issue #13, and also a 48-page special based on Sonic & Knuckles. Neither story actually featured the Death Egg (as that was saved for a later mini-series).
- Sonic the Comic had Robotnik's second Death Egg being stuck on the Floating Island for the span of about 19 issues, the first four of which adapted the plot of Sonic 3, and the last five of which were based on the closing levels of Sonic & Knuckles.
- The Computer Is a Cheating Bastard:
- Inverted in Hidden Palace Zone: Sonic can be airlifted by Tails to a hidden area where there are 30 extra rings. With those and the other rings that aren't hidden, Sonic can turn into Super/Hyper Sonic for the Knuckles battle.
- Worse when Tails transforms, as any boss or enemy (except Knuckles) will get pecked to death by Tails' Super Flickies.
- Without the 7 Chaos/Super Emeralds, however, Knuckles plays this straight; his spin jumps and spin dashes take priority over Sonic's, and he can block your spindashes by crouching. You can't block his. When he's attacking with a glide, however, you can hit him nearly anywhere that isn't his fists. Oh, and he can punch you in the face if you walk too close to him and he's not attacking you.
- Continue Your Mission, Dammit!: See Idle Animation, but also, after Knuckles lowers the bridge for you in Sky Sanctuary Zone, ducking next to him makes him look at your character and wave his arm, as if telling you to go on without him.
- And, in Sonic's continue screen, Tails tugs at his arm while pointing forwards.
- Conjoined Eyes: Particularly noticeable on the Sonic 3 title screen, in which the middle of Sonic's brow actually lowers to seperate his eyes whenever he winks.
- Continuity Nod: Many details and changes in scenery make it clear that, messups aside, Knuckles' story takes place after Sonic defeats Dr. Eggman.
- Convection Schmonvection: Two-thirds of Angel Island Zone is in the middle of a massive forest fire, yet the characters don't seem to mind. And naturally, Lava Reef Zone's lava only hurts you if you actually touch it.
- Conveyor Belt-O-Doom: Death Egg Zone has elevators with conveyor belts that randomly switch direction and try to force Sonic into spikes or gun turrets.
- Co-Op Multiplayer: As in the previous game, a second player can control Tails when playing as Sonic and Tails in single player, the difference being that Player 2 can now fly with Tails as well as pick up Sonic and carry him around. Versus mode is back as well.
- Cutscene Power to the Max: In Knuckles' best ending, he changes into his hyper form with no more than 3 rings, catches the master emerald in midair & holds it with one arm while balancing on a tiny plane thousands of feet in the air. After the credits, he flies into space.
- Demoted to Extra: Tails in standalone Sonic & Knuckles, where he only appears in the closing cutscene if the game is played as Sonic.
- The Determinator: Given how many mechs he goes through, Robotnik certainly comes off as this come the Death Egg and Doomsday Zones. He simply will not give up the Master Emerald no matter what.
- The Dev Team Thinks of Everything:
- Most of the environmental hazards of the game can be rendered harmless with the right shield. Lava Reef Zone is obviously best played with the flame shield, whereas the lightning shield becomes extremely useful for running safely on the electrified floors and ceilings of Death Egg Zone. And of course, the bubble shield (which allows for infinite underwater breathing) is optimal for any level that contains water.
- One subversion is that Knuckles fights Dr. Eggman instead of EggRobo in Flying Battery, breaking continuity due to not using or not being able to implement a unique sprite for EggRobo in that zone. There is a proper EggRobo boss for Knuckles in Carnival Night, should you make your way to the boss with him. Knuckles can also reach one of Sonic's routes in Lava Reef to find a stuck Death Egg in the background, which should be gone.
- Difficult but Awesome: The insta-shield of Sonic's. Slightly increases the range at which you can hurt enemies, and allows you to phase though things like projectiles, invincible enemies and other terrain hazards. It only lasts a split second though, so good timing is an absolute must.
- Difficulty By Acceleration: Used in the Bonus Stages.
- Divergent Character Evolution: While Sonic and Tails played almost identically in Sonic 2, all three characters have specific abilities that can change the way they're played.
- Sonic gains extra maneuverability when he has a shield or is Hyper (he gets a double jump in any direction). His insta-shield extends his hitbox, as well. As a result, Sonic is generally played more aggressively and recklessly.
- Tails has a slightly smaller sprite, and can fly and swim. While flying, his tails become a hitbox. He cannot go Super with only the Chaos Emeralds, but with the Super Emeralds, he gains homing attack Flickies. Tails is generally played more evasively, circumventing level hazards rather than blazing through them.
- Knuckles can glide and climb, and has very poor jump height, which makes it necessary for him to punch through rock walls and access special level routes. Because of his poor jump and unfamiliar levels, and the slow initial speed of his gliding and climbing, Knuckles is usually played cautiously and tactically.
- Dual Boss: The Launch Base Mini-Boss for Knuckles.
- Dueling Player Characters: During the Hidden Palace Zone, Sonic finally gets to fight Knuckles, who had been hindering at every available opportunity after being told by series Big Bad Dr Robotnik that Sonic was in fact the villain of the two. The inverse doesn't happen, as Knuckles' story takes place after Sonic's & he needs to lose the fight to initiate his Heel-Face Turn.
- Dummied Out:
- Much of Knuckles' content is present in the Sonic 3 cartridge, but can't be accessed without attaching it to the Sonic & Knuckles cartridge. Also happens in reverse: in the combined game, when you play Launch Base Zone (the final level of Sonic 3) as Sonic or Tails, the game skips over the original final boss of the level (including the awesome ending music). Though you do still fight it if you play as Knuckles.
- The standalone Sonic 3 cartridge has the Sonic & Knuckles miniboss music dummied out, you can hear it during the Hydrocity Zone Act 1 boss fight if you wait until the drowning music starts, then jump out of the water.
- The standalone Sonic 3 cart also has Mushroom Hill, Flying Battery, and Sandopolis listed in its level select, none of which are accessible without locking onto Sonic & Knuckles, though the incomplete Flying Battery is accessible via hacking. [https://www.youtube.com/watch?v=QKhvt5o9qQc#t=25]
- Another reversed example: the infinite oxygen of the bubble shield is useless in the standalone Sonic & Knuckles, as it does not contain a single underwater section.
- The Sonic & Knuckles music is also in the Sonic 3 cartridge. All of it. In the sound test, most of the Zone music that exists in track 09 onward is from Sonic & Knuckles. So its dummied out in that its not used but its still in the cartridge.
- Easy Levels, Hard Bosses: When you play as Tails, the levels are incredibly easy thanks to his flight, but you'll probably run into a brick wall with some of the bosses thanks to Tails' lack of an Insta-Shield.
- And the Marble Garden boss is especially hard since you will be fighting it alone and cannot jump at it (the only way that Tails can damage the boss is by maneuvering to fly into it from underneath with his propellers).
- Eleventh Hour Superpower: Sonic goes into Super Mode to fight the Perfect Run Final Boss. Though it's less of an Ass Pull, because the player could use the same super mode in any earlier level of the game, and the requirements to fight it are collecting all of the Green Rocks that let you turn into Super Mode. In most subsequent games, the Super Mode is only used for true final bosses.
- Endless Game: Blue Sphere. While not truly endless, per se, 134,217,728 levels would take over a lifetime to beat.
- Eternal Engine: Flying Battery Zone, Death Egg Zone. Also Chrome Gadget from the 2-player mode.
- Every Fifty Thousand Points: You are awarded an extra life every 50,000 points.
- Evil Knockoff: Mecha Sonic. Ironically, in the first two fights, he uses Robotnik's tactics by reusing boss machines from previous games. In Knuckles's playthrough, he's The Man Behind the Man and final boss.
- Faceship: The Death Egg, which has Robotnik's face on it.
- Fire, Water, Lightning: The three elemental shields you could obtain.
- Floating Continent: The setting of the game, although it got knocked out of the sky by the Death Egg's crash landing prior to Sonic's arrival. It gets raised at the end of Sonic's story path and remains afloat throughout Knuckles's until Mecha Sonic steals the Master Emerald, which causes the island to fall back to the sea if the player fails to get the best ending.
- Foreshadowing: When fighting against Knuckles, there is a background mural depicting Robotnik stealing the Master Emerald, and Super/Hyper Sonic attempting to stop him. Guess what you have to do in the true final level?
- Fungus Humongous: Mushroom Hill Zone has mushrooms large enough to bounce on, use as a seesaw catapult, and parachute from.
- Game-Breaking Bug: Many. The American manual acknowledges the possibility of these and Hand Waves them as "diabolical traps" set up by Robotnik, even referring to the problem of having to reset the game or time out due to getting stuck.
- If you kill the Marble Garden Act 1 boss off-screen by using co-op Tails, as soon as the goalpost lands, the game crashes.
- Hyper Sonic is a virtual game breaking machine, since the developers more than likely didn't fully test him, given that he was a last second throw-in that is normally only usable at the end of both games. But start the game back up from the first Act, and you get enough bugs to fill up three hours worth of glitch videos on YouTube. Luckily for most players, many of these are almost impossible to trigger while playing normally.
- The first boss of Death Egg Zone Act 2 is impossible to beat with Super Tails because his Flickies will automatically attack the spiked robots that need to be used to pierce the boss's shield.
- Tails can also trigger several game breaking bugs (usually exploiting the fact that he doesn't clip with objects in the world if he is just off screen), but most of these also require the player to intentionally go out of their way.
- On that note, some copies of standalone Sonic 3 have a real showstopper. Sometimes when you beat the boss of Hydrocity Act 2 as Tails, the screen remains locked in place and won't let you go over to the capsule, thus forcing the player to reset the game and play the entire level all over again.
- The debug cheat allows for a variety of these. One common bug is to enter sprite placement mode while the player character is spinning. The graphics will glitch up momentarily, then the game will reset.
- Gameplay and Story Segregation:
- After the Angel Island Zone is set on fire, there isn't really any dramatic change to the gameplay to indicate that the Zone's on fire. No coming face-to-face with flaming walls or anything. It has basically no gameplay effect whatsoever, aside from one zip line that cuts off fairly quickly because a small section of it is burning halfway down.
- Knuckles shuts off the lights in Carnival Night, but aside from raising the water level for all of 30 seconds, it seems to do nothing except show off how much of a prick he is.
- Giggling Villain: Knuckles whenever he lays traps for Sonic and Tails.
- Gotta Catch 'Em All: In Sonic 3, there are 7 Chaos Emeralds to collect, and getting all of them lets you use the first Super Mode (unless you're playing as Tails). Later, once you get to the Sonic & Knuckles levels, you can power up the gems into the Super Emeralds... and collect them again, for a total of 14 Emeralds. Getting the second set lets you use your character's hyper form (which then lets you use Tails' Super Mode).
- Gravity Screw: Used extensively in Death Egg Zone, as well as the anti-gravity platforms in Carnival Night. Debug mode allows you to reverse the player character's gravity at will.
- Green Rocks / Mineral MacGuffin: The Master Emerald and the various Chaos Emeralds.
- Guide Dang It: In what is probably the most famous example of all time, there is one point in Carnival Night Zone Act 2, where a red-and-white barrel (the Barrel of Doom) is blocking the path. The only way to proceed is by standing on the barrel and pressing up and down on the D-pad as the barrel wobbles. There's absolutely nothing in the game itself to suggest this.
- It is possible to get past it with well-timed jumps (jumping on it is the only action that gives obvious feedback) and turbo spin-dashing under it as it recoils back up, but it is certainly not the intended solution and it's too easy to run out of time trying to pull it off.
- Hailfire Peaks:
- Hand Wave: Hilariously done in the English instruction manual does in regards to certain glitches, where Mercy Invincibility could cause you to get stuck in certain places and be forced to reset the console, which handwaved as one of the "many diabolical traps" set up by Robotnik.
- Hard Levels, Easy Bosses: If you play as Sonic, you don't have Tails' flight to trivialize all the platforming, but the insta-shield gives you a huge attack range, and gives you the ability to bypass protections that certain bosses possess.
- Harmless Freezing: Averted in Ice Cap Zone.
- Hedgehog Cannonball: A common level feature in Carnival Night Zone.
- Hero Antagonist: Knuckles, initially.
- High-Altitude Battle: All the final bosses.
- Also, the boss of Marble Garden Zone Act 2, which is fought by having Tails fly Sonic to chase after it.
- Homage: The item monitors strongly resemble Apple Macintosh computers.◊
- Hoist by His Own Petard: This is how about half the bosses in Sonic & Knuckles are defeated. Let's run it down:
- Eggman's depth charges in the boss fight of Hydrocity are the means by which you launch up to hit him.
- The mid-boss of Carnival Night Zone has a spinning disc with spikes on the edge. The disc is supposed to destroy the floor beneath your feet but if you hit the machine, it opens up and when the disc makes contact, will damage the machine.
- The Act 1 boss at the Flying Battery can be beat by making it hit itself in the head by standing on top of it and running away really quickly.
- The first Act 2 boss of Flying Battery causes the whole place to shudder and collapse by recklessly firing into the floor.
- The mid-boss of Sandopolis will leap into a sand pit (hitting him does no good except throws him backward).
- The boss of Lava Reef is destroyed when his mines slide into him.
- The first boss of Death Egg Act 2 launches rolling spiked mines at you but if you reverse the gravity when the spikes are facing the machine launching them, they will damage it instead of you.
- Horrible Judge of Character: Knuckles believes Robotnik's claims that Sonic and Tails are the bad guys.
- Hub Level: The area where the Master Emerald is kept becomes sort of a Hub Bonus Level when playing the second half of the linked game; entering a giant ring sends you there, where you can choose which Super Emerald you'll try to obtain.
- Humongous Mecha: Robotnik uses one at the end of Sonic & Knuckles.
- Idle Animation: As in the previous games, Sonic will look at the player and tap his foot impatiently if the player does nothing for several seconds, occasionally pointing in the direction he's currently facing. A Dummied Out animation had him falling asleep as well.
- Tails will stare at the player and occasionally yawn.
- Knuckles will start boxing impatiently.
- Immediate Sequel: To Sonic 2.
- Subverted in the manual, which makes it clear that Sonic 3 takes place several months later. But played completely straight for Sonic & Knuckles.
- Inconveniently Placed Conveyor Belt
- Inverted in Hydrocity Zone. Sonic doesn't run on conveyor belts; he hangs from them, and uses them to get to places he couldn't reach without their presence.
- Exaggerated in Death Egg Zone. Some of the conveyor belts are moving platforms which Sonic must take to progress, and they're designed to change direction whenever it's most inconvenient in order to push him into wall spikes or throw him into big ol' bug zappers.
- Infinity–1 Sword: Sonic and Knuckles' super forms. Sure, they are invincible and can move incredibly fast, but that pales in comparison to...
- Infinity+1 Sword: Hyper Sonic and Knuckles. Not only does the hyper form make you just as fast as the super form, but you also get secondary abilities; Sonic gets a double jump that creates a flash that kills all enemies on screen while Knuckles can glide faster, climb walls faster, and create an earthquake that kills all enemies on screen by gliding into a wall. The hyper form also lets you breathe underwater.
- Super Tails is Tails' equivalent to a Hyper form. In addition to invincibility and being able to breathe underwater, he gains an army of Flickies that will shred any enemy that even appears on screen while you just sit there and watch.
- Infinite 1-Ups: Those alarm lights that trigger flying enemies in Launch Base Zone. Hold down a spin dash in one of those alarms, and a constant stream of enemies will fly right into you and be destroyed. The score given for the chain of hits eventually results in one life being granted every 3 secondsnote , and even if you die by time out, since it's before the first checkpoint, you can just walk back there and do it again. There is a limit to how many lives can be recorded, and also a cap on your score.
- Invisible Wall: Appears in a cutscene in Carnival Night Act 2, and just before the first boss battle in Launch Base Act 2.
- Jerkass: Knuckles, until Hidden Palace Zone.
- Kaizo Trap: Some projectiles fired by bosses don't disappear after you beat the bosses.
- The final fight ends with an autoscrolling section where you have to hit the bottom of Robotnik's escape vehicle. Because the floor is crumbling at the same rate that the screen is scrolling, you have to stay on the right side of the screen at all times but hitting the vehicle bounces you to the left & makes you slide a lot. The problem comes when you land the final hit & the screen instantly stops scrolling at the same time that nearly all of the floor suddenly breaks at once. Surviving requires you to be super close to the right corner of the screen when you land the final hit & requires you to land the hit in exactly the right way. Logically, there should be no wrong way because hitting the vehicle should bounce you to the right.
- If you beat the boss of Lava Reef Act 2 while in super or hyper form, you automatically change back to your normal form while likely standing in lava. The lava goes away several seconds later after you've had enough time to lose all of your rings, bounce, lose your mercy invincibility, & die.
- After beating the boss of Flying Battery 2, it's possible to land on the spiked grips of the boss & die.
- After beating the boss of Sandopolis 2, it's possible to die by touching the boss before he finishes sinking into the quicksand. This, like most other cases, is worsened by the fact that super & hyper forms instantly end when you beat the boss of any act.
- Kill It with Fire:
- In Angel Island Zone, Robotnik tries to kill Sonic by firebombing the jungle.
- Then at the end of Lava Reef, he uses the Death Egg's eye lasers to reignite the volcano with Sonic in the middle.
- You can do this to enemies if you have the flame shield as Sonic and use its special attack.
- Lazy Artist: Knuckles fights Robotnik in Flying Battery Zone instead of EggRobo because there was no sprite of EggRobo sitting in the Hang Mobile's cockpit.
- Sonic's super & hyper forms use pallet swaps of many of the sprites of his base form.
- Let's You and Him Fight: Knuckles vs. Sonic and Tails.
- Lethal Lava Land: Lava Reef Zone.
- Levels Take Flight: Flying Battery Zone features a few segments where the player must navigate the outside portions of Robotnik's ship.
- Load-Bearing Boss: The gigantic Eggman mecha at the end of Death Egg Zone. Makes sense, since it not only contains the power source for the whole station, but is also so darn huge that crash landing into the superstructure would certainly do the trick.
- Logo Joke: In Sonic 3, the Sega logo remains in place as a blue ball blazes towards the camera before revealing itself to be Sonic, followed by a white flash that leads into the title screen. In Sonic & Knuckles, the Sega logo remains as the background turns into Angel Island, rumbles and splits apart as the Death Egg crashes on the island's volcano in the background, and voila, title screen.
- Long Song, Short Scene: Some of the music from the individual Sonic 3 gets Dummied Out if you're playing the two games in tandem, including the fantastic miniboss music.
- If you are playing Sonic 3 by itself and do anything that makes the music temporarily change (gain invincibility and have it wear off, start drowning and then jump out of the water, etc.) during either Hydrocity Zone boss, the song will switch to the Sonic & Knuckles mid-boss music instead of going back to the Sonic 3 version. The tune otherwise doesn't appear in Sonic 3 at all.
- The Lost Woods: Mushroom Hill Zone.
- Marathon Level: The stages, compared to previous games in the series, are exceptionally long, but both acts of Sandopolis Zone and Carnival Zone Act 2 definitely stand out. This was possibly done to make up for the small amount of levels after the game was split into two.
- Good luck finishing Death Egg Zone Act 2 (where your time at the end of the stage carries over to the final stage) in under 10 minutes.
- Launch Base Zone Act 2, when playing Sonic 3 alone. The main body of the level can be quick if you know your way around; otherwise you'll be forced into a massive detour. Then you have to fight three bosses, with a cutscene in between that (unlike in the locked-on game) continues to run down the timer. Oh, and the last boss has an annoying phase in which he goes back and forth at the top of the screen, then the bottom; during this period you can't hit him. Like every other stage, your time limit for the entirety of this is 10 minutes. Good luck.
- Magikarp Power: While Sonic and Knuckles unlock their Super Mode after getting 7 Emeralds, Tails doesn't unlock his until he collects all 14 Emeralds. However, his Super Tails abilities (particularly the four birds who will attack any enemies or bosses in Tails' vicinity) are even more of a Game Breaker than Hyper Sonic or Hyper Knuckles in that you can literally kill almost every boss just by standing in one spot (since you're invincible) and letting the birds kill the boss for you.
- Minus World: As Hyper Sonic, you can glitch-dash through walls into areas normally only accessible by Knuckles. A Pandora's Box of further glitches can be triggered from here.
- The Missingno.: Blue Knuckles, and his even glitchier Super Mode.
- Mission Pack Sequel: Sonic & Knuckles to Sonic 3.
- Mirror Boss: Knuckles, if you play as Sonic and/or Tails, though he's ridiculously easy to beat. He is pretty much the same Knuckles you can play as, with the additions of a punch attack and the ability to block by ducking. He even takes Collision Damage, though trying to walk into him will just get you punched. But you can stand in front of him and get Tails to walk into him from behind if playing as Sonic and Tails. Tails takes damage too, but he's invincible (in 2P mode). If Knuckles drops from a glide on your head, only he'll take collision damage.
- Mobile Factory: The Flying Battery Zone.
- Mutually Exclusive Powerups: The three shields.
- New Powers as the Plot Demands: Tails usually tires out after a few seconds of flying, but at the end of Marble Garden Zone he flies for an entire boss fight and then over to the next zone without taking a break.
- Nintendo Hard: At first, Tails appears to be easier to play than Sonic because he has a lot of freedom of movement, including flying and free swimming in water, but fighting the Marble Garden boss with just Tails is immensely difficult because you can only safely hit Robotnik's ship from the underside with your spinning tails while avoiding the drill and the jet exhaust, and it's nearly impossible to recollect any lost rings. Also, unlike Sonic and Knuckles, Tails cannot access a super form with just the Chaos Emeralds. Thus, he cannot access a super mode at all in Sonic 3 and only as early as Flying Battery Zone in Sonic 3 and Knuckles.
- No-Holds-Barred Beatdown: Knuckles in Hidden Palace Zone.
- Non Indicative Name: Marble Garden Zone has a grasshopper badnik named Mantis. Strangely enough, there were actual mantis badniks in the previous game.
- No One Should Survive That: Par for the course with Dr. Robotnik. Upon being defeated in Lava Reef Zone, his craft is engulfed in lava (which instantly hardens).
- Nostalgia Level:
- Hidden Palace Zone is a treat for those who had been wondering about that level that only existed as a song in the options menu of Sonic 2.
- The giant ceiling laser from Flying Battery Zone is a Call Back to Sonic 2's Wing Fortress Zone.
- In Sky Sanctuary Zone, you fight a rehash of the wrecking-ball boss from Sonic 1's Green Hill Zone, and the boss with the spinning things from Sonic 2's Metropolis Zone.note
- Marble Garden's mid-boss uses a burrowing attack based on Mystic Cave's boss.
- Obvious Beta: Standalone Sonic 3 has shades of this; while it is perfectly playable, it clearly shows signs of being rushed. This includes its short length, jaw dropping abundance of glitches (a few of which are game breaking bugs; they are fixed when the game is locked onto the Sonic & Knuckles cart), and the unexciting final boss encounter. This further exemplified by looking at the missing Zones in the Level Select screen, all of which appears in Sonic & Knuckles.
- Obvious Rule Patch: Sonic 3 & Knuckles has this for some bugs which occurred in Sonic 3 alone. Possibly the most blatant example is a music glitch that could occur late in the first Act each of Angel Island and Ice Cap Zones, which had a special-case fix applied for exactly one of the four places which could trigger it.
- Off Model: While watching Death Egg fall at the end of Launch Base 2, Tails has two tiny tails where his normal ones would usually be & two normal ones on the left side of his waist.
- One Game for the Price of Two: If you don't have Sonic & Knuckles, you can't play as Knuckles or play half of the story's levels. If you don't have Sonic 3, you can't play as Tails (with or without Sonic), play the other half of the levels, or do the 2-player mode. And if you don't have both games, you can't use the Hyper Modes (and Super Tails).
- Oxygenated Underwater Bubbles: Present throughout Hydrocity Zone, and can be released by bursting open underwater balloons in Carnival Night Zone Act 2. There's also water in Angel Island, and Act 2 of both Icecap and Launch Base, but you have to use Debug Mode to access the bubble for those levels, as they aren't already placed.
- Oxygen Meter: Particularly funny in light of Death Egg Zone and The Doomsday Zone, as noted above. Sonic can breathe in space, but he still drowns under water. Even Super Sonic can drown. Only Hyper Sonic has Super Not-Drowning Skills.
- Personal Space Invader: Mega Chopper in Hydrocity Zone.
- Player Tic: So who else presses up rapidly on the control pad after beating Robotnik to make it look like the player character is laughing?
- Poison Mushroom: The powerup monitors with Robotnik's face on them.
- Poor Communication Kills: Hidden Palace Zone has a mural showing Robotnik with the Master Emerald in his hands, and Super/Hyper Sonic confronting him. Knuckles misinterpreted this as Robotnik trying to save the Master Emerald from Sonic, and thus treated Sonic and Tails as enemies.
- Power Floats: Super Mecha Sonic. Both of Sonic's super forms also hover above the ground when they're at full speed.
- Power-Up Letdown: Because there are no levels with water from Mushroom Hill onward, the Bubble Shield becomes this.
- Precursors: The former inhabitants of Angel Island. A certain fight in the Hidden Palace Zone takes place before a mural of Super Sonic fighting the True Final Boss of the game, suggesting the presence of Seers.
- Puzzle Boss: Many.
- Carnival Night Zone Act 1: You hit the boss to make it expose its weak point, but the actual damage is done when the bouncing spike platform collides with it.
- Flying Battery Zone Act 1: You trick the boss into hitting itself.
- Flying Battery Zone Act 2: The mini-boss is a laser in the ceiling; you dodge it until it completely tears up the airship.
- Sandopolis Zone Act 1: You beat it by knocking it or luring it into a quicksand pit.
- Lava Reef Zone Act 2: You survive until Robotnik's own attacks destroy his machine.
- Death Egg Zone Act 2: You defeat the first boss by manipulating gravity to hit it with its own mini-bots.
- You can also spin-dash at a minibot that has its spikes stuck in the floor/ceiling to catapult them at the boss.
- The Doomsday Zone: You maneuver so the Robotnik-mecha's own missiles hit it in the face.
- Quicksand Sucks: Sandopolis Zone, and Desert Palace Zone from the 2-player mode. Also, Marble Garden Zone featured tar-like stuff that behaved the same way as the other examples of quicksand.
- Race Against Time: Sandopolis Zone Act 2 is this in spades. Even the boss has a limited time to be defeated before he crushes you.
- Recurring Riff: The "Level Clear" music from this game has been reused by many other Sonic games, and even shows up as Sonic's victory music in Super Smash Bros. Brawl.
- Ring Out Boss: The Sandopolis Mini-Boss, which you have to lure into a quicksand pool.
- Rivals Team Up: Sonic and Knuckles pull this after the latter realizes that he was tricked by Eggman.
- Sand Worm: Wormlike badniks in Sandopolis Zone.
- Scary Scorpions: The Skorp enemy from Sandopolis Zone. Who will almost always get you with their damn tail attack.
- Scenery Porn: Beautiful pixel art, and impressive parallax scrolling on the backgrounds. There are a lot of little cosmetic details to the graphics that were in no way necessary to making the game and are clearly an example of Doing It for the Art.
- Secret Bonus: Complete an act with the clock on 9:59 (one second before a Time Over) and you are awarded 100,000 points, enough for two extra lives. Not easy as it is at that time you must land the critical hit on whatever boss you're fighting.
- Easiest with Knuckles in Carnival Night Act 2, as he doesn't fight a boss. Just stand in front of the capsule until 9:58 or so and then jump and break the capsule. Requires patience.
- Secret Level / True Final Boss: The Doomsday Zone, which is only accessible if you beat Death Egg Zone as Sonic, with a full set of Emeralds, and is just an extended fight with Robotnik's final Egg-Mecha.
- Segmented Serpent: Flying enemies in Angel Island Zone, flying enemies in Mushroom Hill Zone, sand worms in Sandopolis Zone, and yet more flying enemies in Lava Reef Zone. Hitting them anywhere besides the head will injure you.
- Sentry Gun: A few can be seen in Lava Reef Zone.
- Sequence Breaking: It's possible for Tails to skip a few midbosses simply by flying past the area where you fight them.
- Shifting Sand Land: Sandopolis Zone. And Desert Palace from the 2-player mode.
- Shoo Out the Clowns:
- In standalone Sonic 3, after the first boss fight in Launch Base Zone Act 2, Sonic flies Robotnik's hovercraft to the final arena. Tails stays behind and doesn't join Sonic for the two final battles, and Knuckles gets knocked off into the water on the way there. Once Sonic gets off the hovercraft, it's just him and Robotnik.
- In Sonic 3 & Knuckles, when the game is played as Sonic and Tails, the latter disappears once Sonic flies off to face Robotnik in The Doomsday Zone.
- Shout-Out: The final boss and mural seems to be taken from Nausicaä of the Valley of the Wind, while elements of the Floating Island itself, Hidden Palace, Hydrocity, and Sky Sanctuary have similarities to elements of Castle in the Sky.
- The Death Egg is also an obvious reference to the Death Star from Franchise/Star Wars, the only known difference in the appearance being Eggman's face built onto it.
- Slippy-Slidey Ice World: Ice Cap Zone.
- Smart Bomb: When lightning shield meets water, Hyper Sonic does a double jump or Hyper Knuckles hits the wall.
- Smashing Hallway Traps of Doom: Ice Cap Zone and Sandopolis Zone have the most of them.
- Solid Clouds: In Sky Sanctuary, solid clouds serve as trampolines in order to reach higher areas. This is carried over into its appearance in Sonic Generations.
- Songs in the Key of Panic: In The Doomsday Zone, the music speeds up if you're low on rings.
- Spiritual Successor: Flying Battery Zone to Wing Fortress Zone from Sonic 2. Carnival Night Zone would appear to be this to Casino Night Zone from the name, but besides being brash and colourful levels they don't share much in detail.
- The Spiny: There are a few of them.
- Stalactite Spite: The stalactites and icicles in Lava Reef Zone and Ice Cap Zone, respectively.
- Stalked by the Bell: In Sandopolis Zone Act 2, ghosts start to appear as lights in the level go out, and will start attacking unless the player continues to switch new lights on.
- The Stinger: Like in the first game (and the 2013 remake of the second game), after the credits roll a small scene plays.
- In vanilla Sonic 3, failure to collect all Chaos Emeralds shows Dr. Robotnik and Knuckles in possession of them, laughing. Likewise, failure in Sonic & Knuckles or the full game has either Dr. Robotnik or Mecha Sonic claiming the Master Emerald.
- Collecting all Chaos Emeralds as Sonic or Tails in Sonic & Knuckles but not starting the Super Emeralds quest in the full game shows the last EggRobo awakening, which links Sonic and Knuckles' stories.
- Collecting all Emeralds in Sonic 3, or upgrading them in 3 & Knuckles results in the heroes posing by the game's logo.
- Story-Driven Invulnerability: At several points, Robotnik shows up outside of a boss fight but cannot be destroyed.note The most notable instance is during his theft of the Master Emerald.
- Super Not-Drowning Skills:
- Bestowed by a Bubble Shield. Fridge Logic dictates that gas exchange between the water and the giant air bubble would not be able to keep up with Sonic's respiration, so Sonic would still run out of air, but who cares?
- The Hyper forms of Sonic and Knuckles can breathe underwater without the bubble shield, but by the time it becomes possible to get these forms, you've already passed the last level with water in it. Breathing underwater is thus only relevant if you're replaying any of the zones with water on a save file.
- Super Mode: In addition to the usual Super Sonic, it's also possible to play as Super Knuckles. And if you collect all 14 Emeralds you can become Hyper Sonic, Hyper Knuckles, or Super Tails.
- Also Mecha Sonic gains one of these at the end of Knuckles' story as the final boss: Super Mecha Sonic, though in this case he uses the Master Emerald to power his super form (something the Master Emerald has only done here and wouldn't be doing again until Sonic Chronicles ).
- Tactical Suicide Boss: Hot Mobile in Lava Reef Zone. The spikeballs it sends out eventually come back down the slope and hit itself. It's otherwise completely immune to Sonic's/Tails'/Knuckles' attacks (including Super/Hyper forms).
- Temple of Doom: Marble Garden Zone, Hidden Palace Zone.
- Temporary Platform: Some are present in various zones.
- This Is a Drill: All of the bosses from Marble Garden Zone.
- Some regular enemies also have drills.
- Threatening Shark: Inverted. The "Jawz" mook you face in Hydrocity Zone is arguably the easiest enemy to beat in the entire Zone. It slowly propels itself horizontally from offscreen, and while it has a tendency to appear suddenly and in groups, it can be hit anywhere with a spin attack or jump attack. The inversion is that Jawz appears exclusively in Act 2, while the much more bothersome Buggernaut appears exclusively in the Act 1. Hence, Hydrocity is actually better with sharks.
- Timed Mission:
- Every level has a time limit of 10 minutes, which is usually far more than enough. Carnival Night 2 and Death Egg 2 often come close, though.
- In the Doomsday Zone, a second time limit is imposed by Sonic's Super Mode slowly draining the rings in his possession; run out of Super Mode and you fall to your death.
- Used to great effect in Knuckles's version of Sky Sanctuary Zone. Angel Island is slowly sinking in the background and will drop off the screen at the 10 minute mark.
- Totally Radical: The monkey badnik in Angel Island Zone, an obvious update of the similar Coconuts badnik from Sonic 2, according to the manual glories in the name of Monkey Dude.
- Underground Level: Endless Mine from 2-player mode.
- Underwater Boss Battle: The Hydrocity Zone.
- Underwater Ruins: Hydrocity Zone again.
- Unwinnable by Mistake:
- When playing as Sonic with Tails tagging along, it's possible to glitch Tails off-screen so he doesn't return. Doing so in Marble Garden Zone makes it impossible to fight the boss.
- Also, in Hydrocity Zone Act 2, it's fairly easy (though fixed in the locked-on game) to go past the boss and right to the capsule without doing the boss fight. Unfortunately, for some reason, this prevents the level transition cutscene from playing, and while the timer keeps ticking up, you won't die when it hits 10 minutes. The only way out is to reset.
- Video Game Caring Potential: Many fans have commented that they did not have the heart to leave the injured Knuckles on his own in Sky Sanctuary Zone. Perhaps because of this, if you duck near him in just the right spot, he'll make a gesture that quite clearly means "I'll be fine, Go On Without Me".
- Videogame Settings:
- Walk, Don't Swim: Tails can swim. Knuckles can glide in the water. Sonic sinks like a rock.
- Walk on Water: You can run across the surface in Hydrocity.
- Weaksauce Weakness: Fire shields let you run over molten magma and lightning shields make you a ring magnet and immune to electricity, but both are immediately cancelled if you touch water. Annoying in the Sonic 3 portion, with water in 5 of its 6 zones, but not once you reach the Sonic & Knuckles levels which have no water sections at all.
- Weaponized Exhaust: If the boss uses a rocket to fly, it can use that rocket to hurt you. Luckily, though, The Dev Team Thinks of Everything; if you have a fire shield, you're unaffected by the exhaust, giving you a great angle to attack from.
- Weather Control Machine: Featured in Mushroom Hill Zone Act 2.
- What the Hell, Player?: In Competition mode, if one player jumps the starting line before the countdown reaches "GO!", a buzzer plays, "FAULT" appears on their side of the screen, and the round restarts.
- When All Else Fails, Go Right: Averted heavily. The levels steadily go from having to go right to going up, down, or left instead.
- Wrap Around: A few areas in Ice Cap Zone and Sandopolis Zone tend to loop when not exited from them properly. With the Hyper Sonic in Sonic 3 cheat, you can wrap around back to the first act of a Zone, resulting in messed-up graphics and other glitches.
- X-Ray Sparks: When Knuckles gets electrified.