[[quoteright:320:http://static.tvtropes.org/pmwiki/pub/images/Sonic3_title.png]]
[[quoteright:320:http://static.tvtropes.org/pmwiki/pub/images/s-k-title.png]]
[[caption-width-right:320:[[GivingSomeoneThePointerFinger It's not polite to point, Sonic.]]]]

->''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.''
-->-- Words taken from Japanese cover of ''Sonic & Knuckles''.

Creator/{{Sega}}'s third [[The16bitEraOfConsoleVideoGames 16-bit]] entry in the ''[[Franchise/SonicTheHedgehog Sonic the Hedgehog]]'' series, and the followup to the wildly popular ''[[VideoGame/SonicTheHedgehog2 Sonic the Hedgehog 2]]'', was so epic that time and hardware constraints forced them to [[OneGameForThePriceOfTwo 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' PowerTrio, 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' HeelFaceTurn, 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? [[HorribleJudgeOfCharacter 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 [[HeelFaceTurn 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, [[http://info.sonicretro.org/Sonic_3_%26_Knuckles_chronology_and_endings 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 SequelEscalation 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]]Although, if you play as Knuckles, you get to skip the Carnival Night and Lava Reef main bosses, and Hidden Palace is just an interstitial breather.[[/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. CastSpeciation (first introduced in the previous year's 8-bit title ''SonicChaos'') 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 ''[[ExactlyWhatItSaysOnTheTin Knuckles in Sonic 2]]''. The developers attempted to implement a similar feature with the original ''VideoGame/SonicTheHedgehog'', but found [[GameBreakingBug that Knuckles' color palette was incompatible with the game's]] (though a [[GameMod 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 ''VideoGame/BlueSphere'' 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 ''VideoGame/SonicAdventure'', which directly follows this one. ''[[VideoGame/SonicTheHedgehog4 Sonic the Hedgehog 4]]'' is a proper sequel, though the ExcusePlot of ''Episode I'' doesn't suggest it.

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!!Provides examples of:

* ActionBomb: [[http://info.sonicretro.org/Iwamodoki Iwamodoki]].
* AdvancingBossOfDoom / AdvancingWallOfDoom / DescendingCeiling / AutoScrollingLevel / GetBackHereBoss / RiseToTheChallenge: 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.
* AirborneAircraftCarrier: Flying Battery Zone; the Flying Battery also tries to bomb Sonic in Angel Island Zone.
%% Due to a punctuation issue with the page title, you can't use an external link for Caterkiller Jr.
* AirborneMook: Caterkiller, Jr., [[http://info.sonicretro.org/Buggernaut Buggernaut]], [[http://info.sonicretro.org/Jawz Jawz]], [[http://info.sonicretro.org/Bubbles Bubbles]], [[http://info.sonicretro.org/Bubbles Batbot]], [[http://info.sonicretro.org/Star_Pointer Star Pointer]], [[http://info.sonicretro.org/Flybot767 Flybot767]], [[http://info.sonicretro.org/Orbinaut Orbinaut]], [[http://info.sonicretro.org/Butterdroid Butterdroid]], [[http://info.sonicretro.org/Dragonfly Dragonfly]], [[http://info.sonicretro.org/Hyudoro Hyudoro]], [[http://info.sonicretro.org/Fireworm Fireworm]], [[http://info.sonicretro.org/Eggrobo Eggrobo]], [[http://info.sonicretro.org/Spikebonker Spikebonker]], and [[http://info.sonicretro.org/Chainspike Chainspike]].
* AlwaysOverTheShoulder: The bonus stages.
* AmusementParkOfDoom: Carnival Night Zone. Also, Balloon Park from the 2-player mode.
** This is very literal in the minds of many when you consider [[GuideDangIt the barrel.]]
* AncientEgypt: Sandopolis Zone is AncientEgypt [[RecycledInSpace on the Floating Island.]]
* AndIMustScream: [[SubvertedTrope Subverted:]] when you beat the Lava Reef Zone boss, Robotnik sinks into the lava, which cools and hardens seconds later. After the Knuckles fight in Hidden Palace Zone, he's shown to be perfectly fine.
* AnotherSideAnotherStory: ...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 [[http://info.sonicretro.org/Sonic_3_%26_Knuckles_chronology_and_endings here]] for an analysis.
* ArtisticLicensePhysics: 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.
* AttackDrone: As Super Tails, the golden Flickies that follow him serves as such, immediately attacking any enemy or boss that's on-screen.
* BackgroundBoss: The first part of the final boss.
* BagOfSpilling: 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.
* BaitAndSwitchBoss: Knuckles's version of Sky Sanctuary opens with [=EggRobo=] attacking... but then Mecha Sonic (unintentionally) destroys it, and you fight the EvilKnockoff of Sonic instead.
* BatmanCanBreatheInSpace: Death Egg Zone Act 2, and The Doomsday Zone.
* BecauseDestinySaysSo: The mosaics in the background of Hidden Palace Zone are clearly a stylized depiction of Hyper Sonic's fight with the final boss.
* BedsheetGhost: In Sandopolis Zone Act 2.
* BerserkButton: 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.
* BigBoosHaunt: Sandopolis Zone Act 2; the ghosts will pester you (eventually hurting you) constantly if you [[BlackOutBasement don't keep the lights on]].
* BlackoutBasement: Carnival Night Zone Act 2 (for Sonic and Tails), and Sandopolis Zone Act 2.
* BonusStage: 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 [[CheckPoint star post]] with 20 or more rings.
* BookEnds: 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.
* BossOnlyLevel: 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.
* BossRush: Sky Sanctuary Zone.
* BottomlessPitRescueService: With the Marble Garden Zone boss, due to the nature of the battle.
* BrickJoke: 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.
* BuildLikeAnEgyptian: Sandopolis Zone Act 2.
* CastSpeciation
* ChekhovsGun: 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.
* ComicBookAdaptation: In both ''Sonic'' comics:
** [[Comicbook/SonicTheHedgehog 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).
** ''ComicBook/SonicTheComic'' 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''.
* TheComputerIsACheatingBastard:
** 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' [[FeatheredFiend 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. [[CaptainObvious You can't block his]]. When he's attacking with a glide, however, you can hit him nearly anywhere that isn't his fists. [[GoodOldFisticuffs Oh, and he can punch you in the face if you walk too close to him and he's not attacking you]].
* ContinueYourMissionDammit: 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.
* ContinuityNod: Many details and changes in scenery make it clear that, messups aside, Knuckles' story takes place after Sonic defeats Dr. Eggman.
* ConvectionSchmonvection: 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, [[LethalLavaLand Lava Reef Zone's]] lava only hurts you if you actually touch it.
* ConveyorBeltODoom: Death Egg Zone has elevators with conveyor belts that randomly switch direction and try to force Sonic into spikes or gun turrets.
* CoOpMultiplayer: As in the [[VideoGame/SonicTheHedgehog2 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.
* DemotedToExtra: Tails in standalone ''Sonic & Knuckles'', where he only appears in the closing cutscene if the game is played as Sonic.
* TheDeterminator: 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.
* TheDevTeamThinksOfEverything:
** 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.
** 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.
* DifficultButAwesome: 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.
* DifficultyByAcceleration: Used in the Bonus Stages.
* DivergentCharacterEvolution: 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.
* DualBoss: The Launch Base MiniBoss for Knuckles.
* DuelingPlayerCharacters: During the Hidden Palace Zone, Sonic finally gets to fight Knuckles, who had been hindering at every available opportunity after being told by series BigBad 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 iniate his HeelFaceTurn.
* DummiedOut:
** 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 ([[LongSongShortScene 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.
* EasyLevelsHardBosses: 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.
* EleventhHourSuperpower: Sonic goes into SuperMode to fight the PerfectRunFinalBoss. Though it's less of an AssPull, 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 GreenRocks that let you turn into SuperMode. In most subsequent games, the SuperMode is only used for {{true final boss}}es.
* EndlessGame: ''VideoGame/BlueSphere''. While not truly endless, per se, 134,217,728 levels would take over a lifetime to beat.
* EternalEngine: Flying Battery Zone, Death Egg Zone. Also Chrome Gadget from the 2-player mode.
* [[EveryTenThousandPoints Every Fifty Thousand Points]]: You are awarded an extra life every 50,000 points.
* EvilKnockoff: 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 TheManBehindTheMan and final boss.
* {{Faceship}}: The Death Egg, which has Robotnik's face on it.
* [[FireIceLightning Fire, Water, Lightning]]: The three elemental shields you could obtain.
* FloatingContinent: 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 [[spoiler: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?
* FungusHumongous: Mushroom Hill Zone has mushrooms large enough to bounce on, use as a seesaw catapult, and parachute from.
* GameBreakingBug: Many. The American manual acknowledges the possibility of these and {{Hand Wave}}s them as [[ViewersAreMorons "diabolical traps" set up by Robotnik]], even referring to [[UnwinnableByMistake 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 [[http://www.youtube.com/playlist?list=PL01596721403E0594 three hours]] worth of glitch videos on Website/YouTube. Luckily for most players, many of these are almost impossible to trigger while playing normally.
** 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.
* GameplayAndStorySegregation:
** 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.
* GigglingVillain: Knuckles whenever he lays traps for Sonic and Tails.
* GottaCatchEmAll: In ''Sonic 3'', there are 7 Chaos Emeralds to collect, and getting all of them lets you use the first SuperMode (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' SuperMode).
* GravityScrew: 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.
* GreenRocks / MineralMacGuffin: The Master Emerald and the various Chaos Emeralds.
* GuideDangIt: 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 [[DoomyDoomsOfDoom 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.
* HailfirePeaks:
** Angel Island is equal parts GreenHillZone and JungleJapes. Only after a certain point it's [[IncendiaryExponent on fire]].
** Sandopolis Zone is a [[BigBoosHaunt Haunted]] TempleOfDoom in ShiftingSandLand.
** Lava Reef Zone starts off as a straight volcano level, then in Act 2, the lava cools off and there's white crystals everywhere.
** Sky Sanctuary is a [[FloatingContinent castle floating]] among the BubblyClouds.
* HandWave: Hilariously done in the English instruction manual does in regards to certain glitches, where MercyInvincibility could cause you to get stuck in certain places and be forced to reset the console, which handwaved as [[BlatantLies one of the "many diabolical traps" set up by Robotnik]].
* HardLevelsEasyBosses: 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.
* HarmlessFreezing: {{Averted|Trope}} in Ice Cap Zone.
* [[HumanCannonball Hedgehog Cannonball]]: A common level feature in Carnival Night Zone.
* HeroAntagonist: Knuckles, initially.
* HighAltitudeBattle: 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 [[http://en.wikipedia.org/wiki/File:Macintosh_128k_transparency.png Apple Macintosh computers.]]
* HoistByHisOwnPetard: 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.
* HorribleJudgeOfCharacter: Knuckles believes [[ObviouslyEvil Robotnik's]] claims that Sonic and Tails are the bad guys.
* HubLevel: The area where the Master Emerald is kept becomes sort of a Hub BonusLevel 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.
* HumongousMecha: Robotnik uses one at the end of ''Sonic & Knuckles''.
* IdleAnimation: As in the previous games, Sonic will [[BreakingTheFourthWall 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 DummiedOut animation had him falling asleep as well.
** Tails will stare at the player and occasionally yawn.
** Knuckles will start boxing impatiently.
* ImmediateSequel: To ''Sonic 2''.
** Subverted [[AllThereInTheManual in the manual]], which makes it clear that ''Sonic 3'' takes place several months later. But played completely straight for ''Sonic & Knuckles''.
* InconvenientlyPlacedConveyorBelt
** {{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.
* InfinityMinusOneSword: Sonic and Knuckles' super forms. Sure, they are invincible and can move incredibly fast, but that pales in comparison to...
* InfinityPlusOneSword: 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.
* InfiniteOneUps: 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 seconds''[[note]]After you destroy 12 enemies, you get 10,000 points for each enemy destroyed; you get a one-up every 50,000 points.[[/note]], 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. [[SubvertedTrope There is a limit to how many lives can be recorded, and also a cap on your score.]]
* InvisibleWall: 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.
* KillItWithFire:
** 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.
* LazyArtist: Knuckles fights Robotnik in Flying Battery Zone instead of [=EggRobo=] because there was no sprite of [=EggRobo=] sitting in the Hang Mobile's cockpit.
* LetsYouAndHimFight: Knuckles vs. Sonic and Tails.
* LethalLavaLand: Lava Reef Zone.
* LevelsTakeFlight: Flying Battery Zone features a few segments where the player must navigate the outside portions of Robotnik's ship.
* LoadBearingBoss: The gigantic Eggman mecha at the end of Death Egg Zone. [[JustifiedTrope 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.
* LogoJoke: 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.
* LongSongShortScene: Some of the music from the individual ''Sonic 3'' gets DummiedOut 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.
* TheLostWoods: Mushroom Hill Zone.
* MarathonLevel: 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.
* MagikarpPower: While Sonic and Knuckles unlock their SuperMode 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 GameBreaker 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''.
** Combine with Tails' IdleAnimation for an amusing AssKickingPose.
* MinusWorld: 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.
* TheMissingno: Blue Knuckles, and his even glitchier SuperMode.
* MissionPackSequel: ''Sonic & Knuckles'' to ''Sonic 3''.
* MirrorBoss: Knuckles, if you play as Sonic and/or Tails, though he's [[BreatherBoss 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 CollisionDamage, 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.
* MobileFactory: The Flying Battery Zone.
* MutuallyExclusivePowerups: The three shields.
* NewPowersAsThePlotDemands: 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.
* NintendoHard: 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.
* NoHoldsBarredBeatdown: Knuckles in Hidden Palace Zone.
* NonIndicativeName: Marble Garden Zone has a grasshopper badnik named Mantis. Strangely enough, there were actual mantis badniks in the previous game.
* NoOneShouldSurviveThat: Par for the course with Dr. Robotnik. Upon being defeated in Lava Reef Zone, his craft is [[LavaPit engulfed in lava]] (which instantly hardens).
* NostalgiaLevel:
** Hidden Palace Zone is a treat for those who had been wondering about that level [[DummiedOut that only existed as a song in the options menu]] of ''Sonic 2''.
** The giant ceiling laser from Flying Battery Zone is a CallBack 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]]Interestingly, the slight alterations of sprite proportions and game physics made both fights rather different from the originals. The Green Hill boss was originally a WarmupBoss; here he's rather harder to damage without hitting the wrecking ball on the rebound. The original Metropolis Zone boss could only be safely hit at one point in his attack pattern; here, the boss is significantly easier because he can ''also'' be damaged while he's at the top of the screen doing nothing -- plus you have the Insta-Shield to pierce his shield.[[/note]]
** Marble Garden's mid-boss uses a burrowing attack based on [[VideoGame/SonicTheHedgehog2 Mystic Cave's]] boss.
* ObviousBeta: 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''.
* OneGameForThePriceOfTwo: 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).
* OxygenatedUnderwaterBubbles: 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 DebugMode to access the bubble for those levels, as they aren't already placed.
* OxygenMeter: Particularly funny in light of Death Egg Zone and The Doomsday Zone, as noted above. [[BatmanCanBreatheInSpace Sonic can breathe in space]], but he still drowns under water. Even ''[[SuperMode Super Sonic]]'' can drown. Only Hyper Sonic has SuperNotDrowningSkills.
* PersonalSpaceInvader: Mega Chopper in Hydrocity Zone.
* PlayerTic: So who else presses up rapidly on the control pad after beating Robotnik to make it look like the player character is laughing?
* PoisonMushroom: The powerup monitors with Robotnik's face on them.
* PoorCommunicationKills: 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.
* PowerFloats: Super Mecha Sonic. Both of Sonic's super forms also hover above the ground when they're at full speed.
* PowerupLetdown: Because there are no levels with water from Mushroom Hill onward, the Bubble Shield becomes this.
* PuzzleBoss: 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 [[GravityScrew 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.
* QuicksandSucks: 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.
* RaceAgainstTime: Sandopolis Zone Act 2 is this in spades. Even the boss has a limited time to be defeated before he crushes you.
* RecurringRiff: 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 ''[[VideoGame/SuperSmashBros Super Smash Bros. Brawl]]''.
* RingOutBoss: The Sandopolis MiniBoss, which you have to lure into a quicksand pool.
* SandWorm: Wormlike badniks in Sandopolis Zone.
* ScaryScorpions: The Skorp enemy from Sandopolis Zone. Who will [[DemonicSpiders almost always get you]] with their damn tail attack.
* SceneryPorn: 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 DoingItForTheArt.
* [[ScoringPoints 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.
* SecretLevel / TrueFinalBoss: 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.
* SegmentedSerpent: Flying enemies in Angel Island Zone, flying enemies in Mushroom Hill Zone, {{sand worm}}s in Sandopolis Zone, and yet more flying enemies in Lava Reef Zone. Hitting them anywhere besides the head will injure you.
* SentryGun: A few can be seen in Lava Reef Zone.
* SequenceBreaking: It's possible for Tails to skip a few midbosses simply by ''flying past'' the area where you fight them.
* ShiftingSandLand: Sandopolis Zone. And Desert Palace from the 2-player mode.
* ShooOutTheClowns:
** 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.
* ShoutOut: The final boss and mural seems to be taken from ''Manga/NausicaaOfTheValleyOfTheWind'', while elements of the Floating Island itself, Hidden Palace, Hydrocity, and Sky Sanctuary have similarities to elements of ''Anime/CastleInTheSky''.
** 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.
* SlippySlideyIceWorld: Ice Cap Zone.
* SmartBomb: When lightning shield meets water, Hyper Sonic does a double jump or Hyper Knuckles hits the wall.
* SmashingHallwayTrapsOfDoom: Ice Cap Zone and Sandopolis Zone have the most of them.
* SolidClouds: In Sky Sanctuary, solid clouds serve as trampolines in order to reach higher areas. This is carried over into its appearance in ''VideoGame/SonicGenerations''.
* SongsInTheKeyOfPanic: In The Doomsday Zone, the music speeds up if you're low on rings.
* SpiritualSuccessor: 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.
* TheSpiny: There are a few of them.
* StalactiteSpite: The stalactites and icicles in Lava Reef Zone and Ice Cap Zone, respectively.
* StalkedByTheBell: 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.
* TheStinger: 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 [[AWinnerIsYou the heroes posing by the game's logo.]]
* StoryDrivenInvulnerability: At several points, Robotnik shows up outside of a boss fight but cannot be destroyed.[[note]]at least, not without exploiting some {{game breaking bug}}s that allow you to land 256 hits on him.[[/note]] The most notable instance is during his theft of the Master Emerald.
* SuperNotDrowningSkills:
** Bestowed by a Bubble Shield. FridgeLogic 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 [[RuleOfFun 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.
* SuperMode: 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 SonicChronicles ).
* TacticalSuicideBoss: 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'' [[SuperMode Super/Hyper forms]]).
* TempleOfDoom: Marble Garden Zone, Hidden Palace Zone.
* TemporaryPlatform: Some are present in various zones.
* ThisIsADrill: All of the bosses from Marble Garden Zone.
** Some regular enemies also have drills.
* ThreateningShark: 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 [[GoddamnBats much more bothersome Buggernaut]] appears exclusively in the Act 1. Hence, Hydrocity is actually ''better'' with sharks.
* TimedMission:
** 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 SuperMode slowly draining the rings in his possession; run out of SuperMode 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.
* TotallyRadical: The monkey badnik in Angel Island Zone, an obvious update of the similar Coconuts badnik from ''Sonic 2'', [[AllThereInTheManual according to the manual]] glories in the name of ''Monkey Dude''.
* UndergroundLevel: Endless Mine from 2-player mode.
* UnderwaterBossBattle: The Hydrocity Zone.
* UnderwaterRuins: Hydrocity Zone again.
* UnwinnableByMistake:
** 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 [[http://www.youtube.com/watch?list=PL01596721403E0594&v=us93F4qvSVQ&t=565 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.
* UrbanLegendOfZelda: Despite what your third grade friends (and basic logic) told you, it's not possible to beat the Fire Breath the first time you see it and stop it from burning Angel Island. No matter how fast you hit it, it'll successfully set off the firebombs and escape with its robotic life.
* VideoGameCaringPotential: Many fans have commented that they did not have the heart to leave the injured [[spoiler: Knuckles]] on his own in Sky Sanctuary Zone. Perhaps because of this, [[EasterEgg if you duck near him in just the right spot]], he'll make a gesture that quite clearly means "I'll be fine, GoOnWithoutMe".
* VideogameSettings:
** BigBoosHaunt: Sandopolis (Act 2)
** BlackoutBasement: Sandopolis (Act 2)
** BuildLikeAnEgyptian: Sandopolis (Act 2)
** CasinoPark: Carnival Night
** DeathMountain: Marble Garden
** FloatingContinent: Sky Sanctuary
** GreenHillZone: Angel Island
** LethalLavaLand: Lava Reef
** LevelsTakeFlight: Flying Battery
** MarathonLevel: Launch Base (Act 2), Sandopolis (Act 2), Lava Reef
** RemilitarizedZone: Launch Base, Flying Battery
** ShiftingSandLand: Sandopolis (Act 1)
** SlippySlideyIceWorld: Ice Cap
** SpaceZone: Death Egg
** TempleOfDoom: Sky Sanctuary
** TheLostWoods: Mushroom Hill
* WalkDontSwim: Tails can swim. Knuckles can glide in the water. Sonic sinks like a rock.
* WalkOnWater: You can run across the surface in Hydrocity.
* WeaksauceWeakness: 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.
* WeaponizedExhaust: If the boss uses a rocket to fly, it can use that rocket to hurt you. Luckily, though, TheDevTeamThinksOfEverything; if you have a fire shield, you're unaffected by the exhaust, giving you a great angle to attack from.
* WeatherControlMachine: Featured in Mushroom Hill Zone Act 2.
* WhatTheHellPlayer: 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.
* WhenAllElseFailsGoRight: Averted heavily. The levels steadily go from having to go right to going up, down, or left instead.
* WrapAround: 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.
* XRaySparks: When Knuckles gets electrified.
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