Video Game / Sonic Adventure
The fastest thing alive makes the comeback of a lifetime.

Created as the launch title for the Sega Dreamcast, and the highest selling title for the system, Sonic Adventure is one of the first 3D games in the Sonic the Hedgehog series note . It was released in Japan on December 23rd, 1998, receiving releases in North America, Europe and Australia between September and December of 1999.

Sonic Adventure was designed to be to Sega and Sonic the Hedgehog as Super Mario 64 was to Nintendo and Super Mario Bros.: a Killer App designed to be the Video Game 3D Leap to an established mascot franchise that would not only showcase the potential of their flagship console, but also revitalize their flagship series and their own reputation, after they had fallen into both a creative and financial rut during their rocky Sega Saturn years.

Mad scientist Dr. Ivo "Eggman" Robotnik has a new plan to Take Over the World: releasing an ancient morphogenic creature known as "Chaos" from its confinement and using the seven Chaos Emeralds to empower it to world-conquering levels.

Standing between him and his maniacal goals are a team of six heroes, whose adventures unfold in a "Rashomon"-Style plot:

Playable Characters and their gameplay types:
  1. Sonic the Hedgehog — a sarcastic but virtuous blue hedgehog capable of running at supersonic speeds. Sonic's gameplay style is the most reminiscent of the side-scrolling games: Just get to the goal (which is sometimes an animal capsule reminiscent of the Genesis games, sometimes a Chaos Emerald, occasionally just an end area).
  2. Miles "Tails" Prower — Sonic's lil' two-tailed fox adoptive brother, a young genius with an aptitude for building machines on par with Robotnik's creations. All of Tails's stages pit the player against Sonic (and later Robotnik) in a race to the end of the stage. The stages are just a single section of Sonic's stages, hopelessly broken by Tails' flying ability. Sonic is a cheating bastard for this very reason, but even speed boosts can't help him.
  3. Knuckles the Echidna — current Guardian of the Master Emerald. When Chaos is released from the Emerald, it is naturally broken into pieces. Angel Island falls from its place in the sky and into the sea, and Knuckles takes it upon himself to track down the missing pieces and restore the Emerald (and Angel Island) to its former glory. Thus, the goal of each of the echidna's stages is to find three shards, using his Spider-Sense to pinpoint their locations. Reappeared in Sonic Adventure 2 for Knuckles and Rouge.
  4. Amy Rose — a pink hedgehog with an all-consuming crush on Sonic. After she meets a young bird on the run from one of Robotnik's robots, Amy resolves to return the bird to its family. In her stages, Amy must outrun ZERO, the robot in pursuit, and get to the giant balloon that will carry her away. ZERO is actually not after Amy, but instead the bird, who unbeknownst to her, has a Chaos Emerald in its locket. Amy is not very strong or agile, and carries a mallet for protection.
  5. Big the Cat — a lazy but warm-hearted fisherman. After his pal Froggy swallows a strange looking jewel and runs away from home, Big chases after the frog. The goal of each of his stages is to fish Froggy out of a body of water; there is little danger posed to Big himself. Nevertheless, Big's fishing pole can double as a weapon.
  6. E-102 “γ” (Gamma) — one of Robotnik's most advanced robots, who eventually turns against its creator. Shoots things up to get to the end of the stage before time runs out, which can be increased by combo-killing multiple enemies at once. Like Knuckles', this also was re-used for Tails and Robotnik's modes in Sonic Adventure 2.

Re-released for the Nintendo GameCube and PC in 2003 as Sonic Adventure DX: Director's Cut (ironically after its sequel's remake), which added special missions and unlockable Game Gear games. As of September 15th, 2010, it is now available for purchase on Xbox Live Arcade and PlayStation Network, with the DX: Director's Cut extras sold separatelynote . Roughly half a year afterwards, it also saw a release in this manner on Steam.

A direct sequel, Sonic Adventure 2, sold in 2001 to commemorate the series' 10th anniversary, and rumors of a third iteration of the Adventure series linger on, though some argue that Sonic the Hedgehog (2006) was "Sonic Adventure 3" in everything but name.


  • Absurdly Spacious Sewer: Averted with Station Square's sewers, played straight with those of Casinopolis (you get dumped in there if you lose a game of pinball and come away with less than 100 rings or you play the level as Tails).
  • Abusive Parents: Pachacamac didn't have any qualms in ordering his echidna soldiers to trample his own daughter just to get to the Emerald shrine.
  • Action-Hogging Opening: The FMV intro looks far more epic and impressive than most the story depicted in game.
  • A Dog Named "Dog": Big isn't too creative with the names, as his frog friend is named Froggy.
  • Airborne Aircraft Carrier: The Egg Carrier and the Egg Carrier 2.
  • Air-Vent Passageway: The game actually makes use of this trope a number of times in order to progress from level to level.
    • For example, Sonic and Tails travel through the sewers of Casinopolis in order to find the Chaos Emerald located there.
    • This is also how Gamma and Amy choose to travel through the Hot Shelter in the Egg Carrier.
  • All There in the Manual:
    • According an official Sonic website, ZERO is the "zeroth" E-Series robot with the official designation of E-100 Alpha.
    • Said website also states Chaos' origin as a Chao mutated from the Chaos Emeralds' energy.
    • One of the game's official strategy guides gives names E-Series numbers to all of the game's badniks. Said guide also explains a little more of the ancient echidna's backstory, such as Pachacamac's war mongering being pivoted by his mother's death.
  • All Is Well That Ends Well: At the end of the game, as the characters are recuperating after their battle against Perfect Chaos, Tails invokes this trope verbatim, despite the fact that the city has been completely inundated and destroyed.
  • Almost Out of Oxygen: A staple of the franchise. That countdown music is unnerving.
  • Already Done for You: Given that the storylines (apart from the Super Sonic storyline) are done in a "Rashomon"-Style, expect this to happen very often.
  • Amusement Park: Twinkle Park.
  • An Aesop: With Great Power Comes Great Insanity. The tragic story of the Echidna race and Chaos prove this.
  • And Your Reward Is Clothes: Getting all medals unlocks Metal Sonic, who is essentially a reskinned Sonic with slightly altered animations. You can only use him in Trial mode.
  • Animated Adaptation: Was adapted into an arc in the Anime of the Game Sonic X.
  • Another Side, Another Story: Play through the main story from 6 different perspectives. Each character also gets a piece of the backstory of Chaos and the echidna race, only by playing through all stories do you get the complete sequence.
    • And any of the exact same scenes played in multiple stories get alternate dialogue, at least in English.
  • Apocalypse How: Chaos' destruction of the echidna civilization 3000 years ago is a Class 1. Then Chaos' destruction of Station Square is a Class 0 since the citizens possibly survived.
  • Armed with Canon: The localization team pokes fun at the "Robotnik" name debate just before the Egg Hornet battle. Dr. Robotnik throws a tantrum and insists on being addressed by his real name; everyone just ignores him and continues calling him Eggman.
  • Art Evolution: SA1 introduced the art style for Sonic and friends that would be used in future games. Amy was the one affected most by this, as she no longer looks like a pink Sonic in drag. However, the Sonic-themed pinball table in Sonic's version of Casinopolis does feature stock artwork from the earlier games.
  • Artificial Stupidity:
    • Tails' levels have you race against Sonic, who is technically another player controlled by an AI. Because of this, Sonic tends to struggle when dealing with obstacles (which is particularly notable at the end of Casinopolis, where he takes a very long time just to jump through a bunch of spikes), but he makes up for this by rubber-banding his way to the goal. The last race against Eggman averts this because he's not an AI at all, instead he just follows a straight path to the goal.
    • The fights against the other playable characters in the game (such as Sonic vs Knuckles) aren't much better, as they simply charge at you and don't bother dodging your attacks. Because of this, each fight will usually last under twenty seconds.
  • Ascended Extra: Amy, originally a minor semi-recurrer beforehand, gained a prominent playable role in this and many titles following it.
  • Balloonacy: A single balloon is all Amy needs to float away from ZERO's grasp.
  • Bare Your Midriff: Tikal.
  • Battle in the Rain: Sonic's first encounter with Chaos.
  • Big Bad: Eggman, of course.
  • Big Bad Wannabe: Eggman, who Chaos eventually turns on and absorbs the Emeralds.
  • Bigger on the Inside: The Hot Shelter and Sky Deck suggests that the Egg Carrier is this.
  • Big "NO!": Pachacamac belts out one after his conquest invites the wrath of a furious Emerald powered Chaos onto his tribe.
  • Bittersweet Ending:
    • In Knuckles' story, the Rad Red has finally recovered all of the pieces of the Master Emerald and successfully reassembled. However, he's still bound to his mission to guard the emerald alone.
    • In Gamma's story, Gamma dies after destroying his brothers to free the Flickies, but a Flicky of his own is free as well, setting up the ending in Amy's story.
    • In Super Sonic's story, Chaos is neutralized, but Station Square remains a floody mess.
  • Blob Monster: Chaos, who's made of water.
  • Bond Villain Stupidity: Early in Sonic and Tails story following Casinopolis, Eggman successfully ambushes them, sleep gassing them, and stealing their recently acquired Chaos Emerald. Rather than simply using a lethal gas to begin with, or killing them immediately afterwards, he leaves them alone to wake up unharmed the next morning.
  • Bookends: Knuckles' story begins and ends with him narrating how he was fated to stay forever on Angel Island guarding the Master Emerald. In the beginning, he mentions that he doesn't know why he was given this role in life, but in the end, he suggests he may be better off not knowing.
  • Born-Again Immortality: The Chao can come back from death this way if raised correctly. In fact, dying and being reborn twice is one of the requirements for a Chao to become a perfectly immortal Chaos Chao.
  • Boss Arena Idiocy: The arena Amy fights ZERO in is enclosed by an electric fence. If you knock ZERO into the fence, it will reveal a button in its head. Hitting this button damages and ultimately self destructs it.
    • Knuckles would not have defeated Chaos 6 if it weren't for the ice robots scattered all over the arena (for Sonic's fight with Chaos 6, see Tactical Suicide Boss below).
  • Boss Rush: Beating a story unlocks a minigame where you fight each of the bosses faced in that story one after the other (the exception being Super Sonic, whose story only consists of a single boss fight with some Adventure Field navigation beforehand). Gamma's version is strangely restricted to only the Adventure Field battles against E-101 Beta and E-101 Mark II, lacking any of his in-level bosses.
  • Boss-Only Level: Outside of the three E-Series robots not named 101 in Gamma's story, all the boss fights and character duels are self-contained on the main adventure fields (though the last boss fights for Sonic and Tails start right after the player completes their final action stages, but are not directly connected to those stages outside of terrain.)
    • This is also what the final storyline regarding Super Sonic is. This storyline, which appears after everything else in the main story is completed, only has Sonic running to two plot locations in the Mystic Ruins, with the second, done by taking the cart into the back jungle, starts the long series of cutscenes and eventually the Perfect Chaos Final Boss fight as Super Sonic, which is the only challenge in this storyline.
  • Broken Bridge: Parts of the Mystic Ruins, including Angel Island itself, are blocked off by pedestals that require magic stones. The same goes for Station Square, except that the keys are more mundane. Also, after the Tornado crashes, Sonic (who landed in Station Square) and Tails (who landed in the Mystic Ruins) can't reunite because the train isn't running since the workers have gone on strike.
  • But Now I Must Go: Both Tikal and Chaos.
  • Call Back:
    • Icecap first appeared as "IceCap Zone" in Sonic the Hedgehog 3, and it opened with a snowboarding segment, too. Red Mountain's inner section is also clearly part of Lava Reef from Sonic & Knuckles. Both are set on Angel Island.
    • After the Sky Deck minigame, Tails has a flashback to his first meeting with Sonic, originally narrated in theSonic the Hedgehog 2 manual.
    • Amy Rose has a flashback to her kidnapping in Sonic the Hedgehog CD.
    • The ending to Sonic's story mode is more or less a 3D tribute to the ending of Sonic the Hedgehog, complete with Sonic's "YEAH!" Shot into the camera.
    • The cutscene right after the player beats Red Mountain during Sonic's story seems to be a call back to the cutscene before the final level in Sonic 2.
  • The Cameo:
    • NiGHTS, from NiGHTS into Dreams..., has his/her own pinball board in Casinopolis and will even appear in person sometimes.
    • Metal Sonic and Mecha Sonic appear in stasis tubes at Eggman's Mystic Ruins base.
    • Tails Doll (along with doll versions of Knuckles and Sonic) appear as training dummies in Gamma's first level and Sonic's tenth and final level.
    • In the DX: Director's Cut version, Cream the Rabbit appears at certain points in the Adventure Field(mostly Station Square).
    • Chris Thorndyke from Sonic X will appear as a billboard in certain missions.
  • Cannot Spit It Out: A Shrinking Violet in Station Square has a major crush on the guy who works the counter at the Burger Shop. She can't muster up the courage to tell him how she feels, so, she ends up hanging around the shop all day, not saying anything. From his vantage point, she's a Stalker with a Crush. Towards the end of the entire game's storyline, she figures out a way to overcome her problem: get a job at the Burger Shop alongside her object of affection.
  • Captain Obvious: Quite a few snarky moments in SA1, if you look closely.
    (the Egg Carrier changes its shape)
    Tails: Ahhh, wow! It's changed shape. Did you see that?
    (Sonic gives him a weary look, and ignores him)
    Sonic: Darn! This makes it harder for us to get to the bridge!
    Tails: I hate it when he doesn't listen...
    • Also, Gamma, due to being a robot. It states:
    Gamma (when transported into the past via a vision): "This presents a problem."
    Gamma (after seeing what happened to Beta after defeating him at the beginning): "This is the wrong room."
  • Casino Park: Casinopolis.
  • Chaos Architecture: Angel Island looks virtually nothing like it did in Sonic 3 & Knuckles. Here is the original, contrasted to this counterpart.
  • Cerebus Syndrome: This was the first game in the franchise where the tone started to move on from a cartoon tone to a darker, shonen-anime esque tone. The real antagonist, Chaos, isn't a standard "take over the world" bad guy, but a vengeful, mourning creature of god-like power who wiped out an entire civilization (and this is also the first game in the series where characters are explicitly killed, albeit off-screen). The stakes are raised much higher here than in any of the previous entries.
  • Character Development:
    • Tails learns to take on troubles without Sonic's help, and he even musters the courage to stop Eggman's attack on Station Square.
    • Amy goes from being a Damsel in Distress depending on Sonic to save her to an Action Girl beating up the very robot that constantly pursued her.
    • E-102 Gamma learns about love and caring, which motivates it to stop being a mindless servant to Eggman, go on its own mission, and eventually has to die to free the bird trapped inside of him.
  • Characterization Marches On: This game marks the first time Knuckles is portrayed as stoic and serious in contrast to his debut in Sonic 3 & Knuckles where he was constantly laughing at you when he activated one of his traps.
    "Unlike Sonic, I don't chuckle. I'd rather flex my muscles!"
    —"Unknown From M.E.", theme of Knuckles
  • Chekhov's Gun: The Chaos Emerald inside the Tornado 2. It plays a major role in setting off the events for the Super Sonic chapter.
  • Child Prodigy: Tails was implied to have this in previous games, but this is probably the first major series game note which shows the full extent of his technical skills, such as his mechanically powered house and his transforming airplane.
  • Climax Boss: Several for different character modes, mostly aligned to their Character Development:
    • The Egg Walker is the Final Boss of Tails' mode, culminating in him developing independence from Sonic and stopping Eggman on his own.
    • The Sonic/Tails vs E-102 Gamma boss. While pathetically easy whoever you play as, it occurs just after Gamma's Pet the Dog moment releasing Amy from an unknowing Eggman, leading Amy to break up the fight and provoke his Heel–Face Turn.
    • Also E-101 Beta Mk II, Gamma's Final Boss, happening straight after Gamma establishes his Foregone Conclusion that he will sacrifice himself to complete his E-Series rescue mission.
  • Color-Coded Characters: As shown on the character select screen, each character's menu items are shown in a different color:
    • Sonic - Blue
    • Tails - Orange
    • Knuckles - Red
    • Amy - Pink
    • Big - Purple
    • E-102 γ - Gray
  • Comic-Book Adaptation: Was adapted in story arcs in Archie Comics' Sonic the Hedgehog and also as what was notably the last new story arc in Sonic the Comic.
  • The Computer Is a Cheating Bastard: Present in Tails's stages, specifically of the Rubber Band AI variety.
    • More infamous is Chaclon/Chacron, a Chao that shows up in the Chao Races upon their completion. What makes him a cheater is that he's constantly in the "boost" state and runs right past the tree he's supposed to shake.
  • Console Cameo: E105ζ (E-105 Zeta) is made of six Dreamcasts located around the grey blocks under his cannons.
  • Continuity Nod:
    Sonic (to Knuckles): "Did Eggman trick you again?"
    • The music for Twinkle Park's hovercraft and Windy Valley's "The Air" segments are remixes of the Panic Puppet and Green Grove themes from Sonic 3D: Flickies' Island. Also, the second part of Emerald Coast has a Musical Nod to the first boss theme from that game.
    • One of Amy's fantasies is of Sonic saving her in Sonic the Hedgehog CD. However, the models weren't changed.
    • When playing other characters' stories, your allies will sport any power-up accessories you picked up for them in their stories.
    • After getting their powers drained by Perfect Chaos, the Chaos Emeralds look the same as the Super Emeralds looked like in Sonic 3 & Knuckles in their powerless state (except for the size, of course), prior to being fully restored by the player.
  • Convection Schmonvection: Sonic and Gamma can survive just fine in the incredibly hot volcano section of Red Mountain, with lava and geysers being the only hazards that damage them. Then again, this is true of all Sonic games where the characters don't suffer any ill effects from standing only a few inches above a lava pit.
  • Crazy-Prepared: Eggman. Not only does he have the God of Destruction at his command, he has a giant flying carrier (although it functions more like a battleship), a second carrier to use against Chaos if it goes rogue, a HUGE missile stationed off the coast of Station Square should the Egg Carrier and Chaos be defeated, and a giant base in the middle of Mystic Ruins. All of this raises the question, however, of why he needs to gamble with controlling the God of Destruction to destroy just one city with all of these fairly potent back up plans.
  • Creature Breeding Mechanic: Both games include Chao gardens. Chao may be trained and any two may be crossed, with the usual Lamarckian mechanics coming into play. This doesn't affect anything outside of the garden, though.
  • Critical Existence Failure: As in most games in the franchise, Sonic and the cast can take any amount of damage, from a barrage of Eggman's launched missiles to an explosion a third the size of the Egg Carrier, without any outward sign of injury, but after their last ring is lost, brushing against a robot chimp is enough for a K.O.
  • Crystal Prison: The Master Emerald is this to Chaos.
  • Curb-Stomp Battle: In the final route of the game, Eggman hops into the Egg Carrier 2 to tame Perfect Chaos. It's on-screen for maybe ten seconds before Perfect Chaos blows it up.
    • The Sonic/Tails vs Gamma battles usually play the outcome as such, depending on which character is playing. In Amy's case, Sonic is winning, but with Gamma still holding ground.
  • Cutscene Incompetence: In some cutscenes, Sonic is just standing there.
    • He also seems to forget how to run and ends up walking to close distance when he needs to run to prevent something bad from happening.
  • Cutscene Power to the Max:
    • Now we know why Sonic refuses to sit in the cockpit of Tails' plane — because gravity means nothing to him. He survives falling several kilometers to the ground not once, but twice in the game. The second time, Sonic's body endures a comical pancake effect when he hits the ground, but he's no worse for wear.
    • In Tails' ending, he manages to fly all the way from Station Square to the Mystic Ruins without getting tired.
  • Darker and Edgier: At least in comparison to most Sonic games released before it. This game literally starts off with its opening cutscene depicting a city being flooded by Perfect Chaos, and later in the game, the echidna tribe kill the Chao.
    • Gamma's story is this to the rest of the game, complete with an explicitly Bittersweet Ending. Super Sonic's story has a somewhat grimmer tone than the rest of the game as well.
  • Deadly Rotary Fan: Spinner and Thunder Spinner are fitted with these. Speed Highway also features a Helicopter Blender obstacle.
  • Denser and Wackier: Big's story is much more offbeat and light hearted compared to most of the other character modes.
  • The Dev Team Thinks of Everything:
    • When Big enters the sewer elevator, his model is large enough that the door overlaps onto his tail. prompting a sound clip of a door shut and a deadpan "Ow" from Big.
    • If you're thinking bringing a bunch of rings into Casinopolis from the adventure field (probably for an instant emblem), don't bother. The game will just reset your ring count to zero.
    • An unused cutscene exists inside the game's memory for if Gamma quit or lost the Final Egg practice course, where Eggman would scold Gamma and tell him to get back to training. Averted since the cutscene was not implemented into the gameplay itself.
  • Did You Just Punch Out Cthulhu? : The final battle against Perfect Chaos.
  • Dig Attack: Knuckles can dig underground once he finds the shovel claws upgrade. This is mostly used to find Master Emerald pieces that are buried underground starting with Red Mountain (the first Knuckles action stage played after Knuckles obtains the claws) note . Sonic Battle takes this one step further by having Knuckles' burrow ability as a special move, in which after he goes underground, he can move under an enemy and pop up from below to his or her surprise.
  • Didn't Think This Through: Tails modifies his plane so he and Sonic can fly up to the Egg Carrier. This seems to go smoothly until Tails realizes he forgot to equip landing gear just as they're about to land the plane.
  • Doing In the Wizard: In-game, Chaos is consistently portrayed as being some kind of genuine deity that the echidnas worshiped, and having some unexplained connection to the Chaos Emeralds and the Chao—where exactly he came from is never explained in the story. Out of universe, Sonic Channel's profile of the character claims that he is just a Chao mutated by the energy of the Chaos Emeralds.
  • Double Knockout:
    • This happens after the Sonic (or Tails) vs Knuckles fight, both characters run up to each other to attack, only to knock each other to the ground, followed with Sonic or Tails dropping the two Chaos Emeralds, which are then immediately taken by Robotnik/Eggman and fed to Chaos (this creates Chaos 4; the vs Knuckles fight on all sides goes directly to the Chaos 4 boss fight).
    • This can happen in the end of the Egg Viper boss battle, in which it specifically tries to take Sonic down with it.
  • Downloadable Content: Sega released a lot of this, which a player could download onto their VMUs (Visual Memory Unit). You could celebrate Christmas or the year 2000, in addition to the launch of the Dreamcast in the United States, or try to win sportswear from Reebok.
  • The Dragon: Chaos to Eggman. If just to get the Emeralds. E-102 Gamma's role in preserving him and helping against the heroes prior to a Heel–Face Turn may apply them as Co-Dragons.
  • Dragon with an Agenda: Chaos only helps Eggman to get the Emeralds so that Chaos can go One-Winged Angel and destroy the world.
  • Dream Sequence: The visions of the echidnas' ancient history work as this.
  • Dub Name Change: Not unlike Super Mario 64, this game marks the transition from a dub name to the original name and does so by using both, in this case Dr. Robotnik and Dr. Eggman.
    • Outside of the obvious turning point for the series villain, a few minor elements were renamed when the game went International, such as Mystic Ruin to Mystic Ruins and Spina to Spinner.
  • Dueling Player Characters: The game has Sonic and Knuckles fight again, as well as E-102 Gamma. However, playing through as Knuckles and Gamma allows the player to fight Sonic, and playing as Tails puts him in the fights instead of Sonic.
  • Dull Surprise: Due to the technical limitations of 3d modeling from back then, all of the characters have very blank or basic expressions and rigid to nonexistent body language. And then there's Knuckles' absolutely apathetic "oh no" whenever Sonic hits him during their fight.
  • Dummied Out: The game is visibly an Obvious Beta, but aside from the obvious rough edges, some unused textures, music and sprites exist inside the game, at least one unused cutscene (see above), and data listing at least three unmade levels. The DX remake also has a lot of the options and extras from the original's online mode inside it's memory that can be accessed via hacking, such as the extra Twinkle Circuit mini games.
  • Earn Your Happy Ending: All six character stories, though it's rather bittersweet in Gamma's case.
  • Easter Egg: Cream the Rabbit makes a short appearance in the remake. See video here.
    • This one should take a couple minutes to get to - a hidden room
  • Eggshell Clothing: Chao can wear eggshells on their heads.
  • Eldritch Abomination: Chaos, a slime creature whose innards can be seen through it. They get more mechanical as he absorbs more Emeralds, until his final form.
  • Eleventh Hour Superpower: Super Sonic, at the very end.
  • Elite Mook: The E-100 Series robots were designed by Eggman to be more more intelligent and dangerous than his normal Badniks. E-102 Gamma can challenge Sonic just on his own, and in his own story comes seconds from defeating him outright.
  • Eternal Engine: Final Egg.
  • Evil Is Not a Toy: Chaos is only using Eggman so he can destroy the world with the power of the Chaos Emeralds.
  • Exposition Fairy: Tikal is always there to guide the player.
  • Expy: Twinkle Park is one for Sega's "Sega-World" amusement park.
  • Failed a Spot Check: While it's not acknowledged by the characters themselves, Sonic is shocked to hear from Tails that Angel Island has fallen again during the Super Sonic story, despite the fact that he is lying down in view of where it fell.
  • Fanfare: While addressing his robots, Eggman plays his own canned fanfare music. Pretty amusing.
  • Fantasy Kitchen Sink: A superpowered deity, abandoned civilizations, fantasy magic, ghosts, time travel and talking animals are all present in the game, with some science fiction elements and even a "Ghost in the Machine" story for one of the major characters sandwiched in.
  • Filler:
    • Big the Cat's plot has almost no bearing on the rest of the games storyline. The only thing that ties him into it is because his pet frog is hosting and emerald and some essence of Chaos.
    • Similarly Amy's plot is only tied in via the one emerald her Birdie is holding (which is stolen halfway in) and her pivoting E-102 Gamma's Heel–Face Turn, which ironically ends his own relevance to the central story.
  • Five Rounds Rapid: The cops unloading their clips at Chaos 0.
  • Fixed Camera: Made more adjustable in the DX version.
  • Flaw Exploitation: Eggman, once again, tricks Knuckles into fighting Sonic as a way to nab two Chaos Emeralds. To a lesser degree, the first Emerald is nabbed from an opening when Sonic and Tails get cocky post battle.
  • Floating Continent: Angel Island before the Master Emerald was shattered, and Windy Valley.
  • Foreshadowing: The fact that Tikal had actually managed to send Gamma's mental mind to the past foreshadows him becoming sentient in his chapter.
    • At the start of Knuckles' story, when the Master Emerald is broken, you can see a Hint Ball (in other words, Tikal's spirit) fly out of it.
  • For the Evulz: This is about the extent of Eggman's characterization in the game—his only goal is to destroy Station Square so he can build his own evil amusement park, Eggmanland (Robotnikland in the English dub), over its ruins.
  • Four Lines, All Waiting: Six main character storylines that both run alongside and intertwine with each other, with one overarching storyline that most of them loosely tie into (a vengeful monster has been released by the main villain, and is secretly pulling strings to eventually destroy the world).
  • Free Rotating Camera: Not universal though.
  • Freudian Excuse: Pachacamac retroactively gets one through Sonic Chronicles, which reveals that his clan were fighting a losing war against the technologically superior Nocturnus and claiming the Emeralds was a desperate attempt to turn the tides.
  • Friendly Playful Dolphins: Dolphins jump around you in Sonic's first stage, "Emerald Coast", if you're looking in right place at the right time. The appearance of these dolphins and their numbers seems to be performance based, or it might be random.
  • The Friends Who Never Hang: Only Sonic and Tails interact with all five other characters in the story, with Knuckles, Amy, Big and Gamma never really meeting one or two. They can still occasionally find them as generic NPCs to assist in unlocking them however.
  • Futureshadowing: Some of the visions of the past do this. No, seriously.
  • Game-Breaking Bug:
    • Windows will crash in certain times in DX, most commonly during the fight with the Egg Hornet.
    • Don't even think about turning off or resetting the system while saving.
  • Gameplay and Story Integration: In the Chao Gardens, Chao have Resurrective Immortality as long as they're properly cared for. In the story, the Chao who were Chaos' friends kept living through the generations until they were able to meet up with him again in the ending.
    • At the end of Sky Chase Act 1, Tails and Sonic are shot down. If you die during Sky Chase Act 2, Sonic will shout "Not again!" as they're going down.
  • Gameplay Roulette: Sonic Adventure was where all of the Unexpected Gameplay Changes the Sonic series became infamous for started.
  • Genre Shift: The previous games in the series were surrealistic cartoon platformers with science fiction elements. This game shifts the tone of the series to a shonen anime fantasy adventure, and cranking up the science fiction and magical elements far more.
  • Gimmick Level: Sonic's version of Casinopolis has a Chaos Emerald inside of a large vault, on a platform that's too high for Sonic to jump onto. To reach the Emerald you need to fill up the vault with 400 rings so the floor is high enough to jump off of, and to get the rings you need to play pinball (with Sonic as the ball) instead of platforming.
  • Going Through the Motions: Not a major example, but quite noticeable in Amy's ending when she performs her boss victory animation and then abruptly snaps back to her standing animation.
  • Go Through Me:
    • In the backstory, Tikal tries to defend the Chao and the Chaos Emeralds from her dad and his soldiers. Said soldiers brusquely push her aside and proceed to incur Chaos' wrath.
    • In the aftermath of Sonic's (or Tails') fight with Gamma, regardless of who wins, Amy intervenes to convince the victor to let the other live.
  • Gratuitous English: Sonic in the Japanese dub sometimes speaks English with a thick accent, such as when he tells players to "Serect yo kaakta!"
  • Gravity Screw: Most notably in Lost World, where panels on the wall glow when orientated correctly by hitting a switch, allowing Sonic and Knuckles to simply walk up the wall. The last part of Sky Deck changes orientation as well, and Knuckles can actually control this.
  • Growing with the Audience: Prior to this game, the Sonic series was a fairly standard children's video game series in terms of setting and plot. With many of the original Sonic fans grown-up, this game decided to appeal to both older and newer fans with the new direction of the game. The art style took a more realistic bent, and the story dealt with more mature themes such as the genocide of an ancient race, the growing sentience of an otherwise robotic minion, and learning to stand up for yourself, with Character Development for nearly everyone involved.
  • Hall of Mirrors: A segment exclusive to Amy's version of Twinkle Park.
  • Heroic Sacrifice: Before the events of Sonic Adventure, in order to save the world from Chaos' destruction, Tikal sealed him, along with herself, in the Master Emerald.
  • Hijacked by Ganon: Inverted by Chaos taking over the role of central villain from Eggman in the final story.
  • Hints Are For Losers: Touching one Hint Orb in Knuckles' B Rank missions disqualifies you from getting the Emblem.
  • Hong Kong Dub: The lipsyncing is just plain bizarre and off a lot of the time.
  • Hope Spot: Zig-zagged at the end of Amy's story. Birdie is reunited with his family, and everything seems okay... then suddenly ZERO shows up and swats Birdie out of the sky. After ZERO's defeat, Birdie wakes up and is seemingly okay, but as he flies off, he suddenly rapidly drops from sight... only to soar triumphantly back into view and fly off with his family in tow.
  • Hub Level: Station Square, Mystic Ruins, and the Egg Carrier.
  • 100% Completion: Getting all of the emblems entails beating the action stages again, under more challenging circumstances. At most, you have to:
    • Sonic: Finish each action stage within an allotted timeframe.
    • Tails: Beat Sonic or Eggman again (they're faster).
    • Knuckles: Same as Sonic, only the allotted time is one to two minutes.
    • Amy: Same as Sonic.
    • Big: Catch a fish weighing in at 2000 grams and catch Froggy.
    • Gamma: Reach and dispose of a particular target within a certain amount of time left on the clock.
  • I Cannot Self-Terminate: Played with during Gamma's story. Gamma is perfectly capable of self-terminating, it's just that up until the penultimate boss Gamma doesn't realize that his self-given mission technically requires him to kill himself. The moment of contemplation concerning his mortality that he has when he realizes this is almost heart-breaking despite almost no dialogue or music being present in the scene. He ends up averting this trope and allows himself to die from his injuries so that the Flicky inside of him can be freed.
  • I Can't Believe I'm Saying This: Knuckles says this, agreeing with Tails that Sonic is the only one who can harness the true power of the Chaos Emeralds after Perfect Chaos absorbed their negative energy.
  • I Owe You My Life: Not directly stated, but E-102 Gamma's resolve to rescue the animals trapped inside the E-Series robots was partly due to Amy saving its life.
    • Said act by Amy was also provoked by Gamma freeing her and Birdie from Eggman's cell inside the Egg Carrier (which would later crash land into the ocean) making it both issued and returned at the same time.
  • ISO-Standard Urban Groceries: The brown paper bag Amy carries in the introductory cutscene to her story.
  • "I Want" Song: Tails's and Amy's themes: Believe in Myself and My Sweet Passion.
  • Idiot Ball: All three incidents when Sonic and Tails lose Chaos Emeralds to Eggman. The third time this occurs, when two Chaos Emeralds are knocked out of Sonic/Tails's Hammerspace (depending on what character you're being) by a sharp impact. He then proceeds to lie there while Eggman lazily floats over and beams them up.
  • Ignorant of the Call: Most of the cast react this way to Tikal's flashbacks. Near the end of his story Sonic fails to get the message that he should go after Chaos instead of Eggman.
  • Implausible Deniability: Knuckles seems to pull this off after Sonic asked him if he got tricked by Eggman again. This quote from Knuckles' story sums it up:
    "Like, you weren't?"
  • In Case of Boss Fight, Break Glass: The Egg Viper, but it gets harder as you go on.
  • Incoming Ham: Eggman, Eggman, Eggman.
  • Indy Escape: At various points in Sonic's storyline, he has to evade the jaws of an angered orca, an avalanche and an Indiana Jones-esque flaming boulder.
  • Insult Backfire: Sonic calls Robotnik "Eggman", and he protests that his name is Ivo Robotnik. Wait, what does he call himself nowadays?
  • Insurmountable Waist-High Fence: Right towards the end of Twinkle Park for Sonic, there's an iron gate blocking you from getting to a spring if you end up on the right side of it. You can barely jump higher than it by yourself and you can definitely jump higher than it if you get up some speed with a Spin Dash. However, the game won't let you pass it from that side, you have to circumnavigate the entire circular roof to approach the spring from the other side.note 
  • Kaizo Trap: Egg Viper. The camera angle isn't great either, so even if you know his suicide attack is coming, you won't be able to tell where he's gonna hit so you may still die anyway. And beware of losing too many platforms, because the Viper will take you down if it's the last platform remaining. Cue rage.
  • Karmic Death: Implied. Chaos absorbs the Emeralds to transform into Perfect Chaos, wiping out Pachacamac and the echidnas for all of their actions towards Tikal and the Chao.
  • Kick the Dog: Eggman does it a lot in this game. He's portrayed as a lot more evil here than in most portrayals.
    • In the flashback of the final story, Pachacamac ordered the echidna warriors to charge to the Emerald shrine, in which they trampled Tikal and injured the Chao, just so they can seize the Chaos Emeralds. Chaos didn't take kindly of this.
  • Knight of Cerebus: Chaos. He is the first major threat Sonic and co. face that has no humorous quirks or traits whatsoever in persona and design; while his threat is genuine, he isn't seen as much more than a Dragon to Eggman until the climax and finale, when things truly take a turn for the worse when he finally turns on Eggman and gets all of the Emeralds.
  • Last Breath Bullet: The defeated E-101 mk.II gets in one last shot at Gamma before exploding; the shot fatally wounds Gamma and he too is destroyed shortly after.
  • Last Note Nightmare: "Fakery way" for Twinkle Park starts out in a quiet, cute tone, but slowly becomes much more creepy and menacing.
  • Last of His Kind: Knuckles is the only echidna alive. Though Tikal's spirit lingers around after being released from inside the Master Emerald.
  • Leitmotif: Every character is accompanied by their theme tune when they appear.
  • Lens Flare: Present in some of the cutscenes, as well as Emerald Coast and Sky Chase Act I.
  • Lethal Lava Land: Red Mountain, combined with some Death Mountain.
  • Let's You and Him Fight: Eggman tricks Knuckles into fighting Sonic for the second time (or Tails if you play as him).
  • Levels Take Flight: Sky Chase reappears with two acts, and allows Tails to actually fire upon incoming enemies with his Tornado.
  • Long Song, Short Scene: A few jingles and themes were unused in gameplay or for purposes different from how they are labelled (eg. "Calm After The Storm" is labelled as the theme for the crashed Egg Carrier Adventure Field in the Sound Test, but is used only in a short cutscene in Gamma's story). Many tunes were also truncated and can only be heard in full in the games' official soundtrack.
  • Macguffin Delivery Service: Sonic and friends do a terrible job of keeping the Chaos Emeralds away from Eggman and Chaos.
  • Malevolent Architecture: Speed Highway, a highway that uses loop-de-loops, corkscrews and has gaps missing, all while being high in the air.
  • Malicious Misnaming: Sonic calls Knuckles a "Knucklehead" for the first time.
  • Mama Bear: Amy to Birdie. In one instance, she adamantly refuses to give Birdie to Gamma, which then led to his change of heart. In the other instance which stands out more, Amy was enraged when ZERO knocks Birdie out cold and was very keen on bashing him with her hammer.
  • Minion with an F in Evil: E-102 Gamma ultimately.
  • My God, What Have I Done?: E-102 Gamma states this in his story recap following releasing Amy and Birdie and disobeying his master's orders.
  • Mythology Gag:
  • Never Say "Die": Averted, if you listen closely to E-102 Gamma's theme song, the distorted voice in the background repeats: "It's my pleasure. Ready to die."
  • Nice Job Breaking It, Hero!: Knuckles being tricked into fighting Sonic led the two colliding with each other. As a result, Sonic fumbles the two remaining Chaos Emeralds (one of them being green which Knuckles thought was a piece of the Master Emerald), only for Eggman to steal them and power up Chaos into his fourth form. As Sonic best puts it:
    Sonic: Smooth move, knucklehead!
  • Nice Job Fixing It, Villain!:
    • Sonic does not have a way to defeat Chaos 6, but luckily Eggman keeps dropping ice-spewing egg robots onto the battlefield that Sonic can use to freeze Chaos and hit him.
    • E-101 Mark II fires one last shot at Gamma before exploding, killing them both and releasing their Flickies.
    • Eggman's mistreatment of the E-Series and Amy played part in E-102 Gamma's Heel–Face Turn. In Gamma's own story at least, had this not occurred, he would have destroyed Sonic for him.
  • Nobody Poops: Surprisingly averted. One Action Stage (Hot Shelter) contains men's and women's restrooms, both of which can be entered, though not used.
  • No OSHA Compliance: Station Square is a death trap, boasting a highway with loops and a pleasure park containing floating platforms and a hall of mirrors where the flooring tends to give way beneath you.
    • Angel Island's altar is only accessible by a narrow bridge with no handrail over a bottomless chasm.
    • Eggman would be in trouble if a safety inspector took a good look at the Egg Carrier's Sky Deck.
  • Non-Indicative Name: Some of the levels as other characters, who only play in certain parts of them:
    • Casinopolis as Tails takes place entirely in the sewers.
    • Speed Highway as Knuckles features essentially none of the highways and much less speed, due to being an emerald hunting stage at the bottom streets of the city.
    • Gamma's Final Egg is his first level.
  • Obvious Beta: The game was rushed for its original Japanese release and was loaded with glitches, forcing Sonic Team to delay the U.S. release by a year to patch it up. Even then, the game still has loads of glitches, so it's very easy to break wide open, most notably in the DX port, which adds even more glitches than the original Dreamcast game. This page gives many examples of them.
  • Offscreen Moment of Awesome: Somehow Big managed to fly Tails' highly advanced Tornado plane back to his home with zero experience. Sadly we see about a second of him taking off from the Egg Carrier. No Sky Chase minigame for you, Big.
  • Offscreen Teleportation: ZERO in Amy's levels.
  • Offscreen Villain Dark Matter: Eggman was somehow able to build a second, fully functional Egg Carrier right alongside the original, just in time before the final battle.
  • Oh, No... Not Again!: Knuckles says this when he is sent in a flashback in the past for the third time. Also, Sonic says this in his story after encountering Chaos, who has transformed into his 6th form.
  • One-Winged Angel: Chaos becomes Perfect Chaos after he drains the negative energy out of the Chaos Emeralds.
  • Outside-Genre Foe: In almost all of the previous Sonic games, the threat always came from Eggman and his machines, and he simply intended to use the Chaos Emeralds as a means to an end. Chaos is the first major villain in the series to rely entirely on mystical powers instead of the threat of science and machinery to achieve his goals note  and unlike the one-shaded goals of Eggman, Chaos is driven by a vengeful rage to use his power to destroy the entire planet. Even Eggman is left at his mercy when he reaches his full power as Perfect Chaos. He is also the first character in the series to have explicitly killed another character—specifically, he drove the entire Echidna race to near extinction.
  • Palmtree Panic: Emerald Coast. Bonus points as the 2000 Millenium DLC changes the music of this stage to the Trope Namer.
  • Pals with Jesus: Tikal and Chaos, God of Destruction.
  • Panty Shot: Amy belts one out in most of the cutscenes she's in, most prominently when you choose her in the character select screen. This is made unsettling by the fact that she's only 12. And a hedgehog.
  • Papa Wolf: Chaos to Tikal and the Chao, as the echidnas learned the hard way.
  • Path of Greatest Resistance: Ever since Sonic Adventure introduced the Homing Attack, nearly all Sonic games since then have had paths identifiable (and accessible) only by finding a trail of stationary midair enemies. This is most commonly used to begin an expert path or for a shortcut; very rarely is it actually required.
  • Pensieve Flashback: Tikal's M.O. for giving the playable characters Exposition on the backstory of Chaos and the ancient Echidna civilization.
  • Pinball Zone: Sonic's version of Casinopolis features Sonic and NiGHTS-themed pinball tables. Naturally, Sonic is the pinball.
  • Plot Coupon: The Chaos Emeralds and finding them is the main focus of the story for both the heroes and the villain.
  • Police Are Useless: Station Square's police force tries to shoot Chaos 0 but he absorbs all their bullets. Upon discovering this, they immediately retreat.
  • Polygon Ceiling - Most noticeably, the camera is spastic in its best moments, and aspects of the game such as the overworld and mini-games are far less polished than the stages proper.
  • Pooled Funds: Averted; Sonic builds a pile of 400 rings in Casinopolis so he can walk on it to get the Emerald.
  • Poor Communication Kills: Rather than talk to Sonic about why he's after the Master Emerald shards, Knuckles instead immediately starts a fight with Sonic and Tails without reasonably asking the two directly about it, which could have prevented the whole fight in the first place.
  • The Power of Friendship: The bond of Sonic with his True Companions allows him to unlock the full potential of Super Sonic with the Chaos Emeralds, although Tails does say that Chaos only absorbed the negative energy of the Emeralds.
  • The Power of Love: The song playing through this, "Open Your Heart", also suggests it works as this.
  • Raising Sim: The Chao Garden, which can still be done even when the main story is completed.
  • "Rashomon"-Style: Who won in the character vs. character fights? It depends who you ask. Most of the dialogue was re-recorded for each story even when it doesn't need to be.
    • In Sonic and Tails's stories, the character played as is the one who fights most of the bosses and puts the keys in the Mystic Ruins.
    • Also applies heavily to the dialogue in cutscenes that appear in multiple character's storylines. Though the general meaning of what's said stays the same, the exact words will often be different, and sometimes, which character says what will get switched around. Most notably, it occurs in Tails' story, which has large sections that overlap with Sonic'; many of Sonic's lines from his story are given to Tails instead.
  • Ridiculously Cute Critter: This game introduced Chao to the series.
  • Rod And Reel Repurposed : While Big the Cat does use his fishing rod primarily for fishing, he can also use it to attack enemies from a distance if he aims it at them. He can also use his fishing rod as a club if he is standing next to an enemy.
  • The Ruins I Caused: The team looking down upon the flooded Station Square post-Chaos.
  • Rule of Three: Tails' and Knuckles' stories has three bosses, Knuckles gets a vision of the past on three separate occasions (whereas the other five characters only get one), and Amy's storyline has three levels (the fewest level count any character has in this game).
  • Sampling: "Red Hot Skull", the theme that plays in the underground section in Red Mountain, samples its drumbeat from a Hip-Hop remix of "Ghetto Red Hot" by Super Cat (the instrumental version, to be exact).
  • Scenery Porn: It may look a bit dated now, but it was considered highly impressive back then.
  • Sealed Evil in a Can: Chaos was originally sealed in the Master Emerald along with Tikal when he was about to destroy the world, but in modern times, Eggman freed him by destroying the Master Emerald. Subverted however that, when it turns out Chaos isn't actually evil, just very angry and vengeful.
  • Sealed Good in a Can: Tikal, technically.
  • Self-Deprecation: Big surprisingly has a subtle bit of this near the end of his game, supposing that if he must help Froggy on his own since no one would be bothered in rescuing him. Naturally this happens just prior to Sonic offering a team up to save his friend.
  • Self-Serving Memory: While it's not mentioned in the game itself, the official strategy guide gives this as the reason for any differences between the character's stories.
  • Shout-Out:
    • NiGHTS appears in the backgrounds, and the "flying" Chao is shaped like him.
    • A section of Lost World has you being chased by a boulder.
    • At one point, Gamma says "Resistance is futile."
    • Amy's intro cutscene has a bag marked "YU-2 Mart". YU-2 was what Yuji Naka was credited as in the Genesis Sonic games.
  • Shower Scene: Possible in Casinopolis with Sonic if you have him stand under a showerhead, whereupon he'll start scrubbing himself. Knuckles can also trigger the water spray, but he has no custom animation for it.
  • Slippy-Slidey Ice World: Icecap, with an Ice Palace section.
  • Smoke Out: Eggman employs a variety of these tricks, including a flash grenade and sleeping gas.
  • The Smurfette Principle: Out of the 6 characters, Amy is the only female playable character.
  • Space Whale Aesop: Using the good power of magical jewels will give you the superpower to beat up an vengeful deity and make him good again, or at least wise up to what a jerk he was.
  • Spin Attack: Tails can swipe his tails as an attack, which is upgraded to infinite spinning with the Rhythm Badge. Amy can do the Spin Hammer Attack and swing her hammer while spinning, but she can't move while spinning.
  • Spoiler Opening: The opening cinematic contains the destruction of Station Square and Chaos's final transformation. It may have been intentional to prevent players from putting the game down after completing Sonic's story. Or just to get some extra mileage out of the lengthy FMV sequence.
  • Standard Establishing Spaceship Shot: The Egg Carrier's various appearances often start with this.
  • Stock Video Game Puzzle: Quite a few different puzzles appear at varying points across the levels and characters, notably in Lost World.
  • Stuff Blowing Up: Sky Deck is full of cannons and explosions. Twinkle Park also features barrels that, once attacked, explode on a timer.
  • Sudden Name Change: The Floating Island suddenly changed to Angel Island as of this game; Angel Island Zone was the name of the first level of Sonic 3 & Knuckles, but it wasn't the name of the island itself.
  • Suddenly Voiced: Everyone. The early games didn't even have subtitled lines.
  • Tactical Suicide Boss: There are LOTS of them in this game.
    • If Eggman never dug into the ground with the Egg Hornet, Sonic would have never destroyed it.
    • Chaos 2 already has two very effective attacks: one has him bounce all over the arena as a giant ball, and the other covers the entire floor, so why does he have to try to punch Knuckles?
    • Had Chaos 4 never popped out of the water, Sonic, Tails, and Knuckles would have never defeated him.
    • When Sonic fights Chaos 6, Eggman throws ice robots onto the arena. All Sonic needs to do is attack the robot and throw it at Chaos to make him vulnerable. Chaos would have won had Eggman not gotten involved.
    • Eggman should know better than to stick his head out of the Egg Viper.
      • He also should know better than to make its wheels separate from its body and move flat-side up.
  • Team Rocket Wins: Playing E-102 Gamma's story at least, which allows you to fight and defeat Sonic in battle (though Amy stops him just short of finishing the job). So far Gamma is the only one of Eggman's robots to individually defeat Sonic in the games storywise (albeit branching storywise).
  • Teeth-Clenched Teamwork: Knuckles' theme "Unknown from M.E." has a verse which he views teamwork, especially in regards to Sonic:
    I have no such things as weak spots
    Don't approve of him, but you got to trust him
    This alliance has a purpose
    This partnership is only temporary.
  • Temple of Doom: Lost World.
  • That's No Moon!: The excavation team at the Mystic Ruins is flummoxed by a "mountain" which suddenly appeared from nowhere. Unbeknownst to them (and the player, at first), it's actually Angel Island.
  • The Voiceless: Chaos never says a word, and Tikal is the one who relays his feelings to the audience.
  • Theme Song Power Up:
    • Played with in the final battle against Perfect Chaos. "Open Your Heart" (the game's main theme and Super Sonic's personal theme, more or less) plays during the first half of the battle. After you hit Chaos a number of times, it revives and the second half plays out under Perfect Chaos' own theme. It's subverted because Super Sonic doesn't defeat the creature for good while his own theme is playing, inverted because Perfect Chaos' own theme ("Perfect Chaos Revival!") is what plays during the second half (after it's rejuvenated) so Chaos is the one powering up to its own theme, and averted because it doesn't do a lick of good anyway (it's already losing by the time its music starts up; you just have to land the finishing blow (or two (give or take)).
    • Again played with during the Sonic vs Gamma battle. Depending on who you play as, the character with the upper hand will have their theme play as they get ready to land the final blow. Amy will stop them just short of doing so however. In Sonic's case however, it continues so as to be played straight as he heads off to defeat Eggman and Chaos 6.
  • Timed Mission:
    • Tails' stages have him racing against Sonic and, in the last level, Eggman. He has a limited amount of time to get to the goal before they do.
    • All of Gamma's levels and his Final Boss have a 3 minute timer. The timer can be increased by destroying enemies, with the amount granted being larger if more enemies are destroyed at once. The A-Rank versions of his stages shorten the timer.
    • All of the A-Rank versions of the stages, with the exception of Big's levels, have a timer. Since Gamma's and Tails' levels are already timed in the other ranks, the time they are given is shortened.
  • Tranquil Fury: In contrast to his usual Large Ham, Eggman's encounter with Tails in the Egg Walker has him speak this way. Surprisingly, it's very unsettling.
  • Two Lines, No Waiting: The game contains six subplots (seven if you count Tikal's) which all come together in the last story.
  • Uncommon Time: The boss music for Chaos 6 alternates between a 7/8 and a 4/4 time signature.
  • Understatement: Gamma's concise nature of speaking creates such gems as "This is the wrong room" after accidentally walking in on his older brother being seemingly cannibalized for parts and upgraded while still active, or "This presents a problem" after being seemingly teleported back in time.
  • Underwater Ruins: Lost World, in parts.
  • Under the Sea: There's watery segments here and there, but the only extended underwater segments are in Big's stages and are optional.
  • The Unfought: Chaos 1 is never battled, despite having his own unique model.
  • Unusually Uninteresting Sight: Tikal and the other Echidna residents seem completely nonchalant about the heroes' presence, or even a friggin' robot in the flashbacks to the past. About the only reaction they will make is if the player attacks them or jumps on them.
  • Unwinnable by Insanity: In the DX port, if you glitch your way into Twinkle Park with Knuckles and manage to get to the second part of the level, do not put Knuckles into the bowling ball launchers—it'll trap him in place and won't let you launch him, forcing you to restart or quit the level.
  • Updated Re-release: The GameCube DX version, which upgraded the graphics and added some new features and a catalog of Game Gear games.
  • Upgrade vs. Prototype Fight: Gamma the robot is made to fight his "brother" Beta, who is the more advanced of the two. To Eggman's surprise, Gamma wins, so he is charged with carrying out the doctor's missions. Later, Beta is rebuilt and battles Gamma again. Gamma just barely manages to win again, but unlike the previous battle it results in his death.
  • Utopia Justifies the Means: Pachacamac's reasoning for wanting the Chaos Emeralds taken from the shrine. It does nothing to cover up his power hungry nature and lack of regard for life at that point.
  • Video Game 3D Leap: The true first one after the isometric Sonic 3D: Flickies' Island.
  • Video Game Caring Potential: Chao. If you are nice enough to a Chao, it will have a big smile on its face and clap whenever your character picks it up. Beware, however, that being too nice to a Chao might result in the little guy getting a spoiled personality, making it throw tantrums even when only a little hungry. Balance is the key, but regardless, if the Chao is happy enough, it will reincarnate into a baby at the end of its life.
  • Video Game Cruelty Potential: Likewise, you can hit the Chao, throw it, put it in water and watch it flail if it doesn't know how to swim, make it starve, and all other sorts of things. Such abuse will result in the Chao crying a fountain of tears, blowing a raspberry at you, or if it's aggressive enough, it'll charge at you and futilely throw punches. If the Chao is more sad/angry than happy, it won't reincarnate at the end of its life. You can kill your Chao outright this way.
    • Also, in the original Dreamcast version, E-102 could actually shoot the Chao!
    • To a lesser extent, as you play a stage as Sonic with Tails following you, you will find yourself attacking Tails. A few instances in doing this is by jumping in front of him or using a spin dash.
  • Villainous Breakdown: A absolutely chilling one from Eggman at the end of Tails's story, not shown anywhere else. Due to the loss of both Chaos and the Egg Carrier, Eggman snaps and completely ditches his Large Ham and Card-Carrying Villain tendencies and goes from a cackling, somewhat intimidating Mad Scientist to an Omnicidal Maniac with a horrifyingly low growl of a voice. He then attempts to nuke Station Square, and very nearly gets away with it if not for the missile being a dud. After Tails beats him to the missile and disarms it, Eggman snaps further, jumps in a giant spider-mech and resolves to kill everyone himself. This line absolutely seals it:
    Eggman: (in a low growl, directed at Tails) You fool. Away! Before I make mincemeat out of you.
  • Wham Episode: Besides being the series comeback into the mainstream, it shook a lot of things up in terms of content. The threat of Eggman is usurped by a monstrous, magical deity. The Chaos Emeralds are upgraded from bonus power-ups to magical, plot relevant artifacts with an elaborate backstory. The tone is darker and the stakes are raised much higher than previous threats in the series. This was also the first game in the franchise where a character (or rather, an entire civilization) was out-and-out killed.
  • Wham Line: "Units remaining.... Gamma...Beta."
  • What Measure Is a Mook?: E-102 Gamma's story deconstructs this trope by virtue of being a playable mook. (Well, an Elite Mook, but still).
  • Wheel o' Feet: Sonic when running at top speed, but only in the original Japanese release of the game. The International version and all future versions removed the effect.
  • Woobie, Destroyer of Worlds: Chaos. He only acts antagonistically because he has been sealed away so long.
  • Word Salad Lyrics: The themes of Knuckles and Big have their moments, but special mention goes to Amy's Theme:
    I do understand the feelings of a Persian cat
    (But the Sphinx looked so cute I had to shave it)
    He reminds me of parsley when he's standing there all alone
    (Makes me wanna be his speciality)
  • "YEAH!" Shot: All the characters' end of act poses. Sonic and Tails' endings do one as a Call Back to those of the classic Genesis games.
  • You Have Failed Me:
    • Eggman sorta does this to Gamma's E-Series brethren after they fail to retrieve the Chaos-enhanced Froggy, dispatching E105ζ (Zeta) for a torturous upgrade and demoting E103δ (Delta) and E104ε (Epsilon) to random areas.
    • After Sonic, Big, and Knuckles foil their Villain Team-Up one last time and Eggman leaves him for dead on the sinking Egg Carrier, Chaos attacks the doctor out of spite before going solo. An angry Eggman later attempts revenge with the Egg Carrier 2, but Chaos, now in Perfect form, quickly swats him away again.
  • Your Cheating Heart: A couple standing at the elevators at Station Square's hotel are arguing after the woman has discovered that her boyfriend is seeing another woman. Eventually, both women and the man are seen arguing at the swimming pool.