History VideoGame / SonicAdventure2

* AllTheWorldsAreAStage: The final level, Cannon's Core, is played as 5 of the 6 main characters, with all three gameplay styles back-to-back.

** Dark Story characters have fewer levels than their Hero equivalents on average, which means they don't have as many {{Upgrade Artifact}}s to improve their abilities--Shadow has no equivalent to Sonic's Ancient Light, Bounce Bracelet, or Magic Hands, and Rouge has nothing like Knuckles's Oxygen Necklace to protect her from drowning. The only exception is Eggman, who enjoys HardModePerks during the AstralFinale when he gets the Protective Armor in the Cosmic Wall level, which gives him extra health.
** Shadow's BossBattle with the Hot Shot ChickenWalker is almost entirely the same as Sonic's battle with Big Foot, but the Hot Shot has an extra attack, making it the more dangerous of the two.
** Rouge's Egg Quarters level has unique InvincibleBoogeymen enemies called the Egg Beetles, which cannot be defeated at all. Knuckles levels have no equivalent at all.
** Rouge's Mad Space level has a unique gimmick in that the emerald hints are backwards, either [[SdrawkcabSpeech literally]] or [[TheComputerIsALyingBastard metaphorically]]. Knuckles' levels have no equivalent.

* ClassyCatBurglar: Rouge the Bat. In addition to present herself as suave and mysterious, she's also concerned primarily with stealing precious jewels. Also, her motif in her levels' music is {{scatting}} from a tenor female voice.

** In a departure from standard series lore, Sonic actually has more of a beef with Shadow, his {{Alleged Lookalike|s}} and CriminalDoppelganger helping Eggman take over the world, whose escape and terrorist activities have caused GUN to start hounding Sonic. In fact, this is the ''only'' Sonic game to date where Sonic doesn't fight Eggman directly at all.

* AllegedLookalikes: Much of the early plot revolves around Shadow being Sonic's CriminalDoppelganger, which made more sense in the prototype phase of the game's development when the character who eventually became Shadow [[https://i.imgur.com/4qa6Bpp.png still looked like]] Sonic's EvilTwin. By the time of the game's release, Shadow had undergone enough DivergentCharacterEvolution in terms of design that he no longer resembled Sonic, [[EnforcedTrope but this element of the plot was never changed]], so many characters--Eggman, Amy, G.U.N., the media--carry on as if Sonic and Shadow were still identical.

* AffablyEvil: Doctor Eggman, as usual. He's generally an ever-cheerful and pleasant guy, despite his desire to rule the world, and doesn't really want to destroy Sonic like he claims, and though he attempted to do so, he regrets it later, actually stating that he'll miss him. He also manages to get along with Tails in the end. It was also shown that he had his deepest respect for his grandfather.

** The rim of the pit where Eggman first finds Shadow sealed away has some [[https://vignette.wikia.nocookie.net/sonic/images/5/57/Sonic2app_2016-05-27_23-46-53-067.png/revision/latest?cb=20160527205450 tiny writing on the floor]], copy

** The rim of the pit where Eggman first finds Shadow sealed away has some [[https://vignette.wikia.nocookie.net/sonic/images/5/57/Sonic2app_2016-05-27_23-46-53-067.png/revision/latest?cb=20160527205450 tiny writing on the floor]], copy-pasted from [[https://hubblesite.org/contents/news-releases/2000/news-2000-22.html a 2000-era article on black holes]], that says "[[VideoGame/ShadowTheHedgehog ASTRONOMERS ARE CONCLUDING THAT MONSTROUSBLACKS]]".
** During the TrueFinalBoss, Sonic starts to become more and more concerned about Shadow's energy levels, likely because the latter has never used his SuperForm before. [[spoiler:After Sonic and Shadow defeat The Final Hazard, they use Chaos Control to teleport the ARK outside Earth's gravitational pull. Super Shadow's energy gives out immediately after and he plummets to his demise]].
* ForgotICouldFly: Downplayed. After the AstralFinale BossBattle between Knuckles the Echidna and and Rouge the Bat, Rouge is so exhausted she misses her footing and plummets into a SlowMotionFall, only for Knuckles to immediately dive and catch her. By rights, Rouge could probably have saved herself, but Knuckles rescues her before she gets around to it.
* FrameUp: The circumstances surrounding G.U.N.'s relentless pursuit of Sonic--someone who they should know was not the same hedgehog they had [[SealedEvilInACan sealed away in Prison Island]]--are rather suspicious; they're shown pursuing both Sonic and Shadow at roughly the same time, they don't frisk Sonic for the Chaos Emerald he supposedly stole, and they make no move to release him when Shadow returns to Prison Island. Perhaps most damningly, they threw Sonic into a regular prison cell and not Shadow's cryostasis chamber, with no indication that the former was a temporary measure. (As for Shadow and Eggman, neither planned for it, but they're happy to let Sonic and G.U.N. keep each other busy.) This is still a fan theory (and a popular one) at the moment, but it's yet to be seen if anything from the frame-up theory will be confirmed or denied.
** If, and big emphasis on '''''IF''''', this was a case of mistaken identity, then G.U.N. was acting incompetent on so many levels that it becomes comical. In regards to how secret Project: Shadow was, there is the possibility that G.U.N. essentially forgot about it in the sense that all of the present-day personnel are unaware of it. As for chasing Sonic and Shadow at roughly the same time, the operatives must've been miscommunicating, which is highly unprofessional, same with not frisking Sonic. Also, with them not making a move to release Sonic from Prison Island, it seemed to be mostly guarded by robots, but they still should've been keeping a good eye on the cameras. Maybe the reason they act more competently in VideoGame/ShadowTheHedgehog is because they're in the hands of someone who ''knows what he's doing'' and who doesn't want a repeat of the utter ''embarrassment'' that was ''[=SA2=]''.
* FreezeFrameBonus:
** The BlindIdiotTranslation inscribed at the rim of the pit where Shadow was sealed suggests that Shadow had some connection to black alien monsters, indicating that the [[VideoGame/ShadowTheHedgehog Black Arms]] existed in some form as early as this game.
** When Rouge is briefly showing Shadow the paper with information on the [[spoiler:Biolizard]], the text on the document is actually legible and contains some backstory concerning its development.
* FullSetBonus: There is apparently a substantial gap between the power provided by a full set of seven chaos emeralds and the power provided by a mere six. Despite the Eclipse Cannon being able to shatter planets when all seven emeralds are installed, Eggman's initial demonstration with only six of the emeralds can only partially destroy the much smaller moon.
* FunWithAcronyms:
** Subverted with Eggman's theme, "E.G.G.M.A.N.", which is even a SpellingSong--it's spelled out a few times at the beginning by a modulated voice in the background, but it doesn't seem to stand for anything. (Amusingly, it's also one of exactly two songs ever to use the exact phrase "[[Music/TheBeatles I am the Eggman]]".)
** The government military is referred to as "G.U.N.", or "Guardian Units of Nations" (essentially NATO).
* FurryConfusion: Rouge the Bat is a playable character, but cartoony non-anthro bats can be found and rescued from the stages. The level "Death Chamber" takes it even further by adding in realistic bats hanging from the ceiling.
* FurryReminder: When Rouge first introduces herself to Shadow and Eggman on the ARK, she appears hanging ''upside down'' from the ceiling. Just like real bats do when they perch.
* GameMod:
** With the PC release of this game on Steam, [[https://gamebanana.com/games/5855 the mod floodgates have opened]]. Examples include [[http://info.sonicretro.org/Super_Sonic_Adventure_2 playing as Super Sonic in every level]], [[https://gamebanana.com/gamefiles/9413 various restorations and fixes]] to problems with porting, [[https://gamebanana.com/gamefiles/11712 a super]] [[NintendoHard hard mode]], [[https://gamebanana.com/gamefiles/8147 a randomizer]], and many, ''many'' skins.
** There's a still particularly active modding community for the Chao Garden in the Steam version, the two most famous mods being [[https://chao.hippotank.com/forum/viewtopic.php?f=33&t=45060 Chao World Extended]], which can re-add DummiedOut items and add new features, and [[https://chao.tehfusion.co.uk/chao-editor/ Fusion's Chao Editor]], which lets you edit individual pieces of Chao code for certain events to happen, as well as being able to have the normally unobtainable Character Chao.
* GameplayAndStorySegregation:
** All five good vs. evil battles are ultimately seen to end in draws, even though you have to win the actual fight for whichever side you're playing.
** When facing Egg Golem in Hero Story, you have to (as Sonic) get behind it and jump up platforms on its back in order to homing attack its head's weak point to damage it; you need to do this several times. In the Dark Story, it's defeated by Sonic in a cutscene where he takes a giant leap at its weak point (a leap which, incidentally, is not possible when ''playing'' as Sonic) and [[OneHitKO defeats it in one kick.]] However, it comes back to life deranged and unstable, so Eggman has to put his golem down the hard way.
** A minor one, but Shadow's upgrades (the Air Shoes and Flame Ring at least) will be visible on him during his flashbacks with Maria, despite those scenes taking place decades before Shadow had obtained said upgrades in-game.
** Averted in the final boss battle. Shadow's in-story failing super form is represented by his ring count starting lower and lower each time you switch to him after a certain point into the battle.
* GameplayGrading: You are ranked at the end of a stage based on your score (although you can automatically earn a perfect A if you collect ''every single ring'' in the stage[[note]]However this is sometimes impossible due to misplaced rings that can't be acquired normally; see UnintentionallyUnwinnable[[/note]]). The 100 ring and lost Chao missions, as well as the car-driving missions, instead rank you purely on time. All 3D Sonics following this game would use a similar ranking system.
* GameplayRoulette: Not as pronounced as in ''[=SA1=]'', but still present. Sonic and Shadow are speedsters who have to race through platforming, Tails and Eggman control like a third-person shooter with some minor platforming, and Knuckles and Rouge are treasure hunters who have to find three items in each stage.
* GenericDoomsdayVillain: [[DownplayedTrope Not quite Doomsday level]], but the game never shows any real motivation for GUN, so the reason why they pursue Sonic after Shadow breaks out is unclear--it's a toss-up whether it's a deliberate FrameUp to disguise their efforts to recapture Shadow or if they're just [[RightHandVersusLeftHand disorganized]] LawfulStupid {{Inspector Javert}}s pursuing both at once.
* GetBackHereBoss: The second Sonic vs. Shadow battle, which is the FinalBoss of the Hero and Dark storylines. Your opponent races ahead, with you unable to catch up. You have to hit them when they miss with an attack five times to put them down.
* GhastlyGhost:
** Boos are ghosts that serve as common enemies inside Eggman's pyramid base, Pumpkin Hill, and Aquatic Mine; they can grab the player, stopping them in their tracks and leaving them vulnerable to enemy fire. They have one of two faces--either with button eyes and mouths stitched shut like a CreepyDoll or with burning UhOhEyes and an open mouth of razor-sharp teeth.
** King Boom Boo is a giant ghost who serves as [[KingMook the leader of the Boos]] and the boss of Death Chamber. Knuckles fights him, and King Boom Boo is invincible in the dark but [[WeakenedByTheLight weakened when he is exposed to sunlight]]. He has a small ghost following him around to hold an hourglass that temporarily lets light into the arena.
* GiantSpaceFleaFromNowhere: King Boom Boo, the only undead boss in the series, and whom Knuckles happens upon while wandering about the Death Chamber. This is immediately followed up by Eggman being apparently blissfully unaware.
* GoodAllAlong: Rouge the Bat gives the impression of being just another villainous member of the Dark team, being a treasure hunter who antagonizes Knuckles by going after the Master Emerald and assists Eggman in his schemes, but as the story goes on, we learn that [[spoiler:she is an [[TheMole undercover G.U.N spy]] sent to uncover Eggman's world domination plot and the secrets of the Space Colony. Then when Knuckles saves her life, she shows her HiddenHeartOfGold by helping him restore the Master Emerald, and [[{{Tsundere}} even develops a crush on him]]. Rouge is definitely sneaky and [[AntiHero underhanded]] with [[{{Greed}} a big eye]] for jewels, but she [[DarkIsNotEvil isn't bad]].]]
* GotVolunteered: As Sonic and his friends approach to the center of Eggman's pyramid base, they needed a key to get inside. Sonic suggests that Knuckles should find it since he's "the world's greatest treasure hunter", much to his chagrin.
* GRatedSex: Two Chao can produce new eggs by doing a HappyDance. When a Chao is ready to dance, it sits down, displays a big heart above its head, and a ring of freshly blooming flowers sprouts around it. A Chao can even be induced to become more receptive to dancing by feeding it a heart fruit.
* GrandFinale: The Final Story makes all of the characters from both stories playable and [[spoiler:not only reveals the truth behind Shadow, Maria, and the ARK, but finishes with Super Sonic and Super ''Shadow''.]]
* GratuitousEnglish: Sonic in the Japanese dub, as usual for him. Notably, his rank comments are mostly in English (with the exception of B rank, where he literally says "Too easy! Rakushou da ze!" in Japanese and "Too easy! Piece of cake!" in English), his comment of "Hey guy, take care!" after beating Big Foot, as well as a few other examples.
* GratuitousJapanese: The dub has several bizarre instances of Japanese words being left untranslated for seemingly no reason:
** Dr. Eggman's "Yosh!" (Japanese for "Yes!/Alright!")
** A strange case of this comes in "Kick the Rock!", as it's more or less Gratuitous English-Pronounced-in-a-Japanese-Way. The lyrics go "Ekidona, that's what I'm representin'" - "Ekidona" is "echidna" spelled phonetically in Japanese (the singer then adds AccentUponTheWrongSyllable by pronouncing it "Eki-DOH-na").
** Some other examples include Knuckles saying "Ora ora ora!" when digging (carried over from the previous game), and Sonic yelling [[{{Kiai}} "Teriaaaaa!"]] when defeating the Egg Golem in a cutscene.
* GratuitousSpanish: Maria's last line in the Japanese version was "Adios, Shadow the Hedgehog". In the English dub, it becomes GratuitousJapanese instead, as she says "Sayonara, Shadow the Hedgehog".
* GravityScrew:
** Crazy Gadget and its switches that make Sonic walk on the ceiling and walls. A memorable part at the end of the level involves navigating a series of these in space. There are other examples in the part of EternalEngine where Tails floats inexplicably, and Cosmic Wall, where Eggman's mech can jump incredible heights due to lowered gravity.
** Rouge's final level, [[NintendoHard Mad Space]], uses the 'planetoid' subtype very excessively.
* GreaterScopeVillain: [[spoiler:The plot of the game is ultimately due to the actions of the late Gerald Robotnik, who orchestrated a plan to destroy the earth after what G.U.N. did to him. Shadow was the only one in on it, taking advantage of Eggman's megalomaniacal ways to get it done.]]
* {{Greed}}: Rouge the Bat, [[spoiler:who only works with Eggman so she could have a chance to steal the Chaos Emeralds, the Master Emerald, and in addition finish the job for the government where she will get paid with even MORE jewels. [[WordOfGod Oh yes, and she also wants to add her crush and rival Knuckles' heart to that list.]]]]
* GreenHillZone: Rouge's first level, Dry Lagoon, is a textbook example, despite being set in a desert. [[spoiler:The TropeNamer [[NostalgiaLevel makes a return appearance]] if you [[OneHundredPercentCompletion collect all 180 emblems.]]]]
* GrindBoots: Sonic's shoes were redesigned into this. Shadow's are also able to grind.
* GuideDangIt:
** The hidden [[https://www.youtube.com/watch?v=G5lYzoBsaTo Secretary]] and [[https://www.youtube.com/watch?v=ZCL3Zm278_g Maria]] menu themes.
** Some of the "Find the Lost Chao!" Missions are near impossible to complete without looking in a guide. In particular, all the steps that you need to do in [[VeryDefinitelyFinalDungeon Cannon's Core]] to find that Chao is pretty daunting.
*** While not as hard as Cannon's Core, the lost Chao in Radical Highway is particularly easy to miss.
*** Let's not forget that you need a powerup that can be a GuideDangIt in itself to find to complete any of the Lost Chao missions in the first place.
** Cannon's Core. Knuckles' mission is mostly underwater, with [[OxygenMeter all the bubble-inhaling that implies]], unless you found the really well hidden Air Necklace in a previous level which grants him unlimited time underwater.
** Most of the different Chao can be made by experimenting around. The Chaos Chao however have requirements that are so specific you'd probably never know they even exist unless you look up a guide. One of the requirements is giving at least one of each of the TWENTY-ONE different animals to the Chao and have it not be set to a statistical preference (which means it would evolve into a "normal type" otherwise). And once you do that it doesn't even let you know anything changed until a couple hours later when the Chao finally evolves into a Chaos Chao.
** In some of the Hard Mode missions for Knuckles/Rouge levels, some of the emerald pieces are hidden very obscure areas that they won't show up on the radar no matter where you look, and the hint computers don't help much either. Special mention goes to the second emeralds of Wild Canyon and Aquatic Mine.
** In most levels, there is a golden beetle enemy that appears, then disappears after a few seconds. Destroying one of these beetle enemies really helps your rank in score-based missions (the first mission, the timed mission, and hard mode) as doing so gives you 1000 points. However, some of them are very easy to miss, particularly those in Pumpkin Hill, Meteor Herd, Cosmic Wall, Final Rush, and Final Chase.
*** Dry Lagoon in particular deserves a mention, as its Gold Beetle is by far the most difficult one to find and destroy due to being located directly behind a door that requires the Mystic Melody to open. So it's very likely it will have already appeared and disappeared by the time the door is opened, and you will have no idea it was even there in the first place.
* GustyGlade: There's a giant air current in the middle of Wild Canyon. Knuckles has to jump into it so it can propel him to the upper parts of the level.
[[/folder]]

[[folder:H-P]]
* {{Hammerspace}}: How Knuckles carts around his emerald pieces. (At least Rouge can claim to have a [[VictoriasSecretCompartment compartment]]).
* TheHeavy: Shadow dominates the story of the game: he's introduced after the first level in both storylines, his release drives GUN crazy--Shadow even gives Eggman his newest EvilPlan, so [[TheManInFrontOfTheMan the events of the game are his doing]]. The Dark Story is a dive into Shadow's backstory.
* HeroAntagonist: Sonic, Tails, and Knuckles are this in the Dark Story, with Sonic himself serving as the final boss of the campaign.
* HeroicSacrifice: [[spoiler:Shadow, after turning face in what is quite possibly the most famous example of this trope in a ''Sonic'' game. Overlaps with RedemptionEqualsDeath.]]
* HeroRivalBaddieTeamUp: In the Last Story, [[TheHero Sonic]], [[TheLancer Knuckles]], and [[TheRival Shadow]] infiltrate the core of Space Colony ARK together. Knuckles uses his incantation to control the Master Emerald, while Sonic and Shadow use the Chaos Emeralds to transform and fight the [[FinalBoss Biolizard]].
* HiddenHeartOfGold: Rouge. Despite her introductory cutscene showing her to be a vain "treasure hunter" with ulterior motives, her first stage requires her [[VideoGameCaringPotential to rescue a turtle held captive by GUN robots]], prompting the turtle to gift her with access to the second half of the level. At no point does the game tell you the turtle will help you, so Rouge's rescue of the turtle is largely for the sake of the rescue itself.
* HintsAreForLosers:
** {{Downplayed}} in the Treasure Hunt stages, where using hints lowers the bonus earned when collecting the relevant treasure. That said, the stages score primarily on speed, so using hints won't necessarily lock players out of an A-Rank.
** {{Exaggerated}} in Rouge's Mad Space level, where the the hint monitors are reversed, as the hints either say [[GuideDangIt the opposite of where the Emerald Shard really is]], or are literally written backwards.
* HistoryRepeats: Tails enters the Hero Story [[StormingTheCastle raiding Prison Island]] to bust out a certain hedgehog--the Dark Story reveals Eggman raided the island even before he did to bust out ''another'' [[TheHeavy certain hedgehog]].
* HoistByHisOwnPetard: At one point, Eggman sics the Egg Golem onto Sonic. In Dark Story, Sonic destroyed the restraining bolt on the Egg Golem. [[AIIsACrapshoot Guess what it does with Eggman afterwards?]]
* HolidayMode: The original Dreamcast release of the game offered Halloween- and Christmas-themed DownloadableContent, usually {{Palette Swap}}s of the playable cast.
* HongKongDub: When the line takes longer to say in English than it did in Japanese, the next line will start while the previous one is still going... even when the next line is spoken by the same character. (It does lend a strange David Mamet flavor to the dub.)
* HostageForMacguffin: Eggman takes Amy hostage near the end of the game in order to get the last Chaos Emerald needed for the Eclipse Cannon off of Sonic and Tails. Or so we thought, see OutGambitted below.
* HotterAndSexier: This isn't the first game in the series to toy with {{Fanservice}}--Tikal's top in the original ''Sonic Adventure'' is quite revealing--but [[MsFanservice Rouge the Bat]] is [[ShamelessFanserviceGirl so up-front about it]] that this game blows all previous titles out of the water.
* HowDidYouKnowIDidnt: Downplayed since the Dark Side story revealed Eggman knew, or at least suspected, that the heroes had a fake Chaos Emerald when he saw two readings for the final one show up on a monitor, knowing full well he had the other six. When he finally brought this up to Sonic and friends, Eggman just [[BluffTheImpostor pretended like he knew for sure]], only to get proven right when [[YouJustToldMe Tails slipped and asked how he knew the Emerald wasn't real]].
* HumansAreTheRealMonsters: Shadow's initial viewpoint, as well as Gerald Robotnik's. Though that's because [[spoiler:GUN got cold feet on Project Shadow and forced the whole thing to be shut down, accidentally shooting Maria in the process, sending both Shadow and Gerald into despair]].
* HumongousMecha: G.U.N.'s Big Foot, Hot Shot, and Flying Dog, which serve as a WarmUpBoss for Sonic, Shadow, and Rouge, respectively. While they're big, they're also relatively slow with attacks that are easy to dodge.
* {{Hypocrite}}: Rouge accuses Shadow of invading her privacy when he reveals he knows her true identity, [[spoiler:while her entire job is to infiltrate Eggman's inner circle and investigate the ARK computer for information on Project SHADOW]].
* HypocriticalHumor:
** In one scene where Eggman steals the Master Emerald from Knuckles:
--->'''Rouge:''' Thief!\\
'''Knuckles:''' [[LampshadeHanging Look who's calling who a thief!]]
** In the Last Story where Eggman learns about his grandfather had planned for [[spoiler:the ARK to crash towards the earth]]:
--->'''Eggman:''' That mad scientist!\\
'''Amy:''' That should be you, right?
** Also the scene where Amy breaks Sonic out of jail (after trying to wring a marriage promise out of him).
--->'''Amy:''' ''(after Sonic runs away)'' Wait for me, Sonic! ''(to herself)'' He's such a brat sometimes!
* IAmBecomingSong: "Supporting Me", the BGM for the Biolizard BossBattle, is Shadow's meditation on his new outlook on life, looking to the future, acknowledging his need for Maria's support, [[spoiler:and his acknowledgment that he won't have it anymore]].
* IAmGreatSong:
** Invoked and inverted with "Rhythm and Balance" (the theme for White Jungle), which consists of Shadow insisting, over and over again, [[SuspiciouslySpecificDenial that he's not scared]][[note]]In the story, Shadow is racing to save Rouge's life, having been provoked by memories of Maria.[[/note]]--i.e. the song is not about how Shadow is fearless so much as it's about how he's in denial.
** Invoked with "The Supernatural" (the theme to Final Chase) where, instead of establishing Shadow's character to the audience, it's Shadow re-affirming it to ''himself'', after Rouge's revelations about Project Shadow have caused him to doubt his own identity.
--->''I am the ultimate life, the perfect existence''
--->''Nothing is unpredictable to me, nothing can surprise me''
** Subverted with "For true story", which is about how the various pleasures and glories of nature are ''supposed'' to be utterly insignificant to the UltimateLifeForm ("Stars don't twinkle, the moon doesn't shine... To the pure body, to the perfect experience.")... and also about how Shadow is skirting the edge of the DespairEventHorizon (''i.e.'' because [[InexplicablyAwesome Sonic is somehow able to match him]], which undermines Shadow's whole vision of reality).
* IAmSong:
** Sonic's, Knuckles', and Eggman's {{Image Song}}s ''It Doesn't Matter'', ''[[BoastfulRap Unknown from M.E.]]'', and ''[[VillainSong E.G.G.M.A.N]]'', respectively.
** The BGM of many of Shadow's and Knuckles's is a look into their psyche and how they see themselves.
** The lyrics of ''Escape from the City'' explain the basics of Sonic's personality to the player.
* ImageSong: All six playable characters, as well as Amy, have one. Sonic's, Tails', and Knuckles' themes are remixes of their original Adventure themes, while Amy's is exactly the same.
* InMediasRes:
** Almost every character is introduced in the middle of doing something-- the only one who isn't is TheHeavy.
*** Sonic first appears breaking out of a helicopter where he was being held captive by GUN.
*** Tails enters the plot ''en route'' to raid Prison Island and rescue Sonic (and Amy got there even before he did).
*** Knuckles and Rouge both enter the scene bickering LikeAnOldMarriedCouple over the Master Emerald that Rouge stole.
*** Eggman appears first either in the Hero story stealing the Master Emerald while Knuckles and Rouge argue or in the Dark story raiding Prison Island.
*** Shadow first appears either in the Hero story ([[AvertedTrope in the calm following the fight]] with the Big Foot) to make an ominous speech or in the Dark story being un-{{sealed|Evil In A Can}} by Eggman.
** The Hero Story itself doesn't begin until well after the Dark Story plot has kicked off.
* InTheirOwnImage: In the BuildLikeAnEgyptian desert stages, enough of the original iconography remains to suggest that the whole region was originally echidna territory--according to the background music, Knuckles's Wild Canyon stage in particular is explicitly ancestral land. That hasn't stopped Eggman from plastering his face nearly everywhere both in and around his pyramid base.
* IndecipherableLyrics: All the themes from Shadow's stages have distorted lyrics that are hard to make out, but "The Supernatural" and "Supporting Me" take this up to eleven in that some of their lyrics are so distorted that you're unlikely to realise that they're even ''there'', let alone what's being said. For example, "The Supernatural" supposedly includes the line, "Tell me the truth, are you really the ultimate life?" -- contrasting with Shadow's insistence that he is, and reflecting his state of self-doubt after [[spoiler:Rouge shows him the article about the Biolizard]] -- but good luck making it out.
* InformingTheFourthWall: If you attempt to have Knuckles or Rouge dig on a surface too tough for them to dig into, they'll tell you "I can't!"
* InsultToRocks: Shadow finds it almost insulting that G.U.N. mistook Sonic for him.
-->'''Shadow:''' "You're not even good enough to be my ''fake''!"
* InterfaceScrew:
** The Mad Space hint monitors give you wrong or reversed directions.
** TimeStandsStill when Action Race or Treasure Hunt characters use their final SpecialAttack in multiplayer mode, making the opponent freeze and preventing them from being controlled. (Amy Flash only prevents the opponent from being controlled; it doesn't freeze the target). The frozen character must wait out a timer before being freed, but can accelerate it by ButtonMashing.
* InterimVillain:
** G.U.N. serves as [[MeleeATrois a generally antagonistic force that harries and opposes both the Hero and Dark characters]] before both sides can properly decide things during the AstralFinale.
** In order to keep either Knuckles and Rouge from collecting the others' emerald shards and ending the Master Emerald sub-plot too early, they don't encounter each other until [[RivalFinalBoss after all their story missions have been completed]]. In order to make sure all playable characters have at least two {{Boss Battle}}s during the story, however, King Boom Boo appears [[GiantSpaceFleaFromNowhere from nowhere]] to give Knuckles a fight earlier on and Rouge has to fight against Flying Dog in Security Hall.
* InterruptingMeme: Some of the dialogue have characters interrupting each other's sentences right before they end it due to having to time dialogue with the Japanese lip movements; sometimes it works, other times it causes the dialogue to overlap or be said to soon. Take the prelude of the first Sonic vs. Shadow fight for instance:
-->'''Shadow:''' You're comparing yourself to me? Ha! You're not good enough to be my f--\\
'''Sonic:''' I'll make you eat those words!
* InvincibleBoogeymen: The Egg Beetles in Rouge's second stage, Egg Quarters, which patrol the rooms for intruders, and, if they find one, attack it with lasers. They cannot be defeated and can only be dealt with by hiding in the shadows out of their sight. Luckily, they glow so bright that they illuminate the whole room in their light when they enter.
* {{Irony}}: Sonic in prison. Not only is the FastestThingAlive unable to go anywhere while behind bars, not only is he unable to look for clues (which is his explicit purpose on the island, no less), the biggest clue of all is [[RoomFullOfCrazy his own cell]], which he doesn't appear to have noticed.
* ItsPersonalWithTheDragon:
** In a departure from standard series lore, Sonic actually has more of a beef with Shadow, his {{Alleged Lookalike|s}} and CriminalDoppelganger helping Eggman take over the world, whose escape and terrorist activities have caused GUN to start hounding Sonic. In fact, this is the ''only'' Sonic game to date where Sonic doesn't fight Eggman directly at all.
** Inverted with Tails and Eggman, whose rematch during the AstralFinale is an example of "ItsPersonal with the {{Sidekick}}," [[spoiler:thanks to Eggman having Sonic ThrownOutTheAirlock]].
* ItRunsInTheFamily:
** The Robotnik family [[StrongFamilyResemblance mustache]]!
** The Robotnik family genius!
** The Robotnik family need to build {{Faceship}}s!
* IWasJustPassingThrough: Two instances of this had happened.
** Shadow shrugs off of the fact he saved Rouge's life, and says that he was saving the Chaos Emeralds.
** Knuckles does this to Rouge after saving her from falling down the lava, claiming that he was saving the pieces of the Master Emerald.
* IWillShowYouX: Shadow says this on a few occasions. On example is when you play as Sonic, Shadow says this to him in the start of their battle aboard the ARK:
-->'''Shadow:''' Before this is over, I will show you the true power of Chaos Control!
* JigglePhysics: Different parts of different characters have this, the most notable examples being Sonic and Shadow's quills, and Rouge's ears and breasts.
* JumpScare: The boos in the haunted stages will pop up at the character's face while growing large in form before disappearing. They will do this when in miniature forms if the character gets close to it or just pop up from random places unseen, even in some of the areas where one of the Master Emerald shards is located.
* JungleJapes: Green Forest and White Jungle, which serve as the respective fifth and ninth action stages in the Hero and Dark stories, take place in a jungle. Both of these stages have a [[TimedMission time limit]] due to Eggman setting up bombs to destroy Prison Island.
* JunglesSoundLikeKookaburras: Though not the actual call, White Jungle's soundtrack features a ''very'' kookaburra-like sound in the percussion at the beginning.
* JustAKid: Eggman insults Tails for being a kid in the beginning of their first battle:
-->'''Eggman:''' You're just a kid! You couldn't beat me in a hundred years, stupid little fox!
* KarmaHoudini: The G.U.N. squad that raided the ARK fifty years ago appears to have never suffered punishment. Their attempts in the current day to capture Sonic all end in disaster for them, however.
* KeepItForeign: Maria's final words in the Japanese version are "[[GratuitousSpanish Adios]], Shadow the Hedgehog". In the English version it's "[[GratuitousJapanese Sayonara]], Shadow the Hedgehog".
* KickChick: Rouge, to contrast Knuckles' punches only attack style.
* KillSat: Space Colony ARK has a giant laser, which Eggman uses to great effectiveness to [[spoiler:blow up part of the moon with the power of only one Chaos Emerald]].
* KillTheCutie: [[spoiler:Poor Maria. She did nothing wrong, and yet she gets killed in the confusion when G.U.N. comes onto the Space Colony ARK to forcefully shut down Project Shadow.]]
* KnightTemplar: G.U.N. will do almost anything to preserve world order. They got better eventually. Also, Gerald believed his [[spoiler:ColonyDrop against humanity]] to be "justice" for the ARK Disaster.
* KnightTemplarBigBrother: Shadow was a surrogate one for Maria, [[spoiler:until Amy reminded him what Maria really wanted.]]
* LadyAndKnight: Maria Robotnik and Shadow the Hedgehog are an unusual pair of Bright Lady and Dark Knight. Maria is the pure and beloved granddaughter of the [=ARK's=] head scientist, while Shadow is TheUnfettered LivingWeapon who will ruthlessly pursue whatever objective he needs to in order to fulfill her wishes.
* LaserGuidedKarma: Knuckles' emerald-shattering punch is a two-fer for Eggman, who is not only suffering the natural consequences of attempting to steal the Emerald right in front of its Guardian, but is also getting comeuppance for his attempted theft of the Master Emerald in ''VideoGame/Sonic3AndKnuckles'', where Knuckles instead tried to wrestle it from his machine's claw and only got electrocuted for his trouble.
* LawyerFriendlyCameo: The President is not named, bears no likeness to any real American president, and the presidential logo looks nothing like the real one.
* LeaningOnTheFourthWall: After you defeat [[FinalBoss Shadow]] for the second and last time in the Hero Story, Sonic quips "Game over, Shadow!" Considering that boss battle is the last bit of gameplay in the Hero Story, the BondOneLiner can be applied to both Shadow and your game time.
* LeaveHimToMe:
** Sonic tells the other heroes to leave Eggman to him when Eggman confronts them in the pyramid base, leading to the Egg Golem boss.
** In the Last Story, Shadow, after realizing Maria's true wish, tells Sonic and Knuckles to leave [[spoiler:The Biolizard]] to him while they head to the Master Emerald shrine.
* LeeroyJenkins: Sonic, even more so than usual. He's concerned only with stopping Eggman and pays little attention to Tails' strategy sessions.
* {{Leitmotif}}: Many songs throughout the game feature the same recurring guitar riffs, along with some shared lyrics (for instance, in "City Escape" and the chorus of "Supporting Me"). It's only at the end of the game that they come together into the game's signature theme, "Live and Learn".
* LethalJokeCharacter: Amy Rose is easily the slowest of the Action Race multiplayer characters but has several dangerous advantages.
** Amy's {{Special Attack}}s cost half as many rings as Sonic's or Shadow, so competent players can SpamAttack their opponents by just making sure to collect as many rings as possible.
** TimeStandsStill for the opponent when Sonic and Shadow use their final special attack, arresting their momentum and preventing them from moving. Not so with Amy's, which just [[InterfaceScrew suspends the opponent's controls]]--anywhere there's SomeDexterityRequired, a well-timed attack from Amy will all but guarantee the opponent loses a life and ''still'' must wait out the remainder of the freeze.
** Amy may be the slowest at running, but she has an unusually fast grinding speed, so [[ThisLooksLikeAJobForAquaMan rail-centric stages give her an extra advantage]].
* LevelGrinding: Completing all of the Chao Garden emblems will require quite a bit of this. Not only do you need to pump your Chao full of stat-boosting animals and shards, but you need to keep completing quests to do it.
* LikeAnOldMarriedCouple: There's a distinctly light-hearted mood to all of Knuckles' and Rouge's arguing. Knuckles smugly lets himself be distracted when boasting about the Master Emerald's power long enough for Eggman to sneak up BehindTheBlack and seize it, and Rouge adds to the silliness by panicking and throttling Knuckles once he breaks it. After their battle during the AstralFinale, Knuckles and Rouge are seen using the exact same words and tone to demand the other relinquish the Emerald, and after Knuckles rescues Rouge, she develops a distinct soft spot for him[[note]]''Adventure 2'' notably [[NoEndorHolocaust ignores the severity of stealing the Master Emerald]] (i.e., Angel Island [[ColonyDrop falling from the sky]]); it's possible that this was meant to keep the tone of their arguments lighthearted[[/note]].
* LostInTranslation: ''Sonic Adventure 2'' has some of the screwiest translation of any game in the series, with several scenes having their tone shifted or dialogue that doesn't convey what was originally in the Japanese script. A GameMod for the 2012 PC version attempts to rewrite the subtitles so, when played in Japanese, an English-speaking player can experience a more accurately translated script.
* LuckBasedMission:
** Getting a good rank in the Treasure Hunting stages requires the player to find all three treasures in the stage [[TimedMission as soon as possible]]. Since the treasures' locations are randomized and the radar only works on one at a time, however, getting a good set of easy-to-access locations requires the RandomNumberGod's favor.
** Chao Karate gives control of your Chao to an AIRoulette and an ill-timed CriticalHit mechanics can screw you over. Sufficiently LevelGrinding your Chao will mitigate (if not remove) the effect that the RandomNumberGod has, as the Chao's stats will eventually be strong enough to dish out huge damage and/or take very little in return.
** Chao races feature an actual hidden luck stat in some races, along with randomized tripping.
* MadScientist:
** The ManBehindTheMan. [[spoiler:Prof. Gerald Robotnik was sane prior to GUN's assault on the ARK. After that his disillusionment with humanity drove him to strike back with his creation. \\
\\
Even when he wasn't a MisanthropeSupreme, Gerald Robotnik was at least tremendously eccentric--activating the Eclipse Cannon causes the ARK to lose half of its mass and become a FaceShip, the center of the colony is designed using the iconography of ancient Echidna culture, and the hordes of Artificial Chaos and the Biolizard all indicate he was a MakerOfMonsters]].
** And then, there's Eggman, of course. As usually, he's more of a standard example of the cackling type of MadScientist.
* MadScientistsBeautifulDaughter: {{Downplayed}} by Maria Robotnik, whose grandfather Prof. Gerald Robotnik was at minimum quite eccentric, [[spoiler:even if he wasn't yet an OmnicidalManiac]], as seen by his exacting recreation of ancient echidna culture and making the ARK into a secret FaceShip.
* MagicMusic: The Mystic Melody upgrade, which can be acquired by all the six playable characters. It can allow a character to play a "mystical melody" with a transverse flute when near to the ancient ruins, creating new pathways in a stage. The Mystic Melody is essential for the "Find the lost Chao" missions.
* MarathonLevel:
** Cannon's Core, the only action stage in the "Last" story. It's a multi-stage level that involves every playable character minus Shadow (who gets saved for the boss battle following Cannon's Core).
** While not as long in terms of actual length of gameplay, Cosmic Wall does take awhile thanks to the conveyor belts Eggman needs to get between sections. To put this in persective, it has the highest time limit of any TimedMission in the game at eight minutes (even Cannon's Core is only seven and otherwise no level goes above five).
* MechaMooks: The G.U.N. mechs are the recurrent enemies of the game. Eggman's badniks appear as well, but only for the pyramid levels.
* MeleeATrois: The Prison Island section is essentially a three-way bout between [[TheHero Sonic]] and friends, [[BigBad Eggman's]] [[VillainProtagonist group]], and [[KnightTemplar G.U.N.'s]] military presence.
* MergingTheBranches: The Hero and Dark paths each end in a similar place, with Tails fighting Eggman for the real Chaos Emerald while Sonic battles Shadow over the fake one. The Hero and Dark endings each imply their protagonists won their duels, but both lead into the Last Story. Some subtle details show how both endings are true: in the Hero ending, Eggman is seen swiping the real Emerald behind Tails' back while they assume he's unconscious, so whether he wins or loses, he winds up with the final Emerald. The Dark ending doesn't show the aftermath of either battle, simply cutting to Eggman triumphantly inserting the final Emerald into the machine, and beginning an Evil Laugh while, behind his back, an error pops up on the control screen, indicating something has gone wrong with the Eclipse Cannon firing (implied to be Gerald Robotnik's booby trap activating and seizing control of the colony). So either ending can lead into the Last Story, which has all seven Emeralds plugged into the machine, but the Eclipse Cannon not firing for one reason or another.
* MetalSlime: Gold Beetles only appear for a brief moment in one specific part of each level, and vanish just as quickly. Destroying one nets you a huge amount of points for your score, which go a long way towards earning a better rank for certain level requirements.
* MetropolisLevel: The game has a few levels in the Central City. City Escape takes place in a San Francisco-esque neighbourhood complete with running down streets and escaping from a giant GUN truck, while Mission Street and Radical Highway are located within the city highways above the skyline, both include running away from authorities.
* MightyGlacier:
** Tails and Eggman's mechs are much slower and clunkier than everyone else, but possess great firepower that lets them destroy armies of {{mook}}s easily and have health bars that allow them to endure multiple hits without rings.
** Amy, Chaos, the Dark Chao mech and Eggman's alternate costume in the multiplayer mode. They all run slower than their competition, but Amy can spam special moves for less rings than everyone else, Chaos has extra range on his attacks and can breathe underwater infinitely, the Dark Chao mech has the strongest attacks and alternate Eggman is even slow and can't lock onto targets but possesses brutally strong shots.
* MiniMe:
** It's possible to raise Chao that can resemble Sonic, Shadow, and (although not showing up physically in this game) [[VideoGame/NightsIntoDreams NiGHTS]]. Special Chao that look like Tails, Knuckles, and Amy Rose also exist, though they're unobtainable by normal means.
** The Neutral Chaos Chao greatly resembles a smaller [[VideoGame/SonicAdventure Chaos 0.]] Raise one from a Shiny Blue Egg and the resemblance is even more uncanny.
* MiniMecha: Tails and Eggman's stages consist of piloting small mechs, with Tails' Cyclone being his new Tornado airplane [[TransformingMecha that swaps its wings for a set of legs]] and Eggman's being his Eggmobile with legs and guns attached.
* MirrorBoss: Each character fights their [[EvilCounterpart Hero/Dark counterpart]] twice, or in Knuckles/Rouge's case, once. [[SecretAIMoves The enemy characters can use moves from multiplayer fights]], but the player can't.
* MirrorCharacter: Deep down, Rouge and Knuckles are both stubborn and proud. Lampshaded after their BossBattle, where they SpeakInUnison, each demanding the other stop fooling around and return *their* emeralds.
* MisplacedRetribution: Gerald's plot to get revenge from beyond the grave was focused on bringing suffering and ruination to people (Pretty much the entirety of humanity) who were not responsible for the ARK Incident or the murder of Maria and his colleagues.
* MoreThanMindControl: It's heavily implied that Gerald "reprogrammed" Shadow to go along with his genocidal ColonyDrop plan.
-->'''Gerald''': I designed its mind to be perfect. Pure...
* MouthStitchedShut: The Boom Boos from the Death Chamber level have these that conceal their {{Slasher Smile}}s.
* MovesetClone: The game gives three sets - Shadow to Sonic, Eggman to Tails and Rouge to Knuckles.
* MsViceGirl: Rouge is secretly a government agent whose job is to protect the world from threats like Eggman and Shadow, and turns out to be GoodAllAlong. Also, her passion is jewels, and in her free time she goes around greedily stealing gems wherever she can find them, not caring whether they're, y'know, necessary to the balance of the planet or not. Somehow, these two things never seem to clash -- in fact, she's apparently only a good guy some of the time because the government pays her in jewelry.
* MsFanservice: This game introduced the world to Rouge the Bat. She has a big bust, [[{{Stripperific}} a revealing outfit]] combined with JigglePhysics, [[HartmanHips and wide hips]] that go hand in hand with a shapely rear.
* MusicalNod:
** City Escape appears as an instrumental in [[https://www.youtube.com/watch?v=EUZBu0gELsw Mario & Sonic at the Olympic Winter Games]].
** The CallBack to [[VideoGame/SonicAdventure Lost World]] in Cannon's Core is also this. There is a water slide similar to the aforementioned level in Adventure, and the music changes to the drum beat of the music that was used in the water slide part of that level.
*** The music played during the cutscenes before and after the Biolizard reuses some parts of the music played during Lost World as well.
** The Chao Race music used in this game got remixed for the main menu theme in [[VideoGame/SonicAdvanceTrilogy Sonic Advance 3]].
** The melody at the beginning of City Escape's lyrics [[https://www.youtube.com/watch?v=bKNj60pZHTo has the same rhythmic motif]] as an early segment from ''VideoGame/{{Sonic 3|And Knuckles}}'''s [[https://www.youtube.com/watch?v=5SKcTZNeRnQ Endless Mine]]. This connection was made more explicit in City Escape's Classic Remix from ''VideoGame/SonicGenerations'', which directly samples the original Endless Mine track.
* MythologyGag: The Egg Golem first appeared as the boss of Sandopolis Zone Act 2 in ''VideoGame/Sonic3AndKnuckles''. It also bears a striking resemblance to Guardian, the boss of Sandopolis Zone Act 1. Plus, both Egg Golem bosses are fought inside a pyramid.
** Eggman attempts to steal the Master Emerald in the exact same way he did in ''VideoGame/Sonic3AndKnuckles'', even using the exact same machine to do it.
** Sonic's introduction cutscene before his City Escape level is a reference to something that was DummiedOut of ''VideoGame/Sonic3AndKnuckles''. Originally in that game, Flying Battery Zone was going to come in between Carnival Night Zone and Ice Cap Zone, and the level transition would have had Sonic using the door of the Flying Battery as a snowboard in Ice Cap. In the cutscene before City Escape, Sonic uses the door of the G.U.N. helicopter as a skateboard.
* NeverSayDie: Averted. Dr. Eggman comments in one of his story reminder monologues that killing Tails will be a pleasure, Sonic is told on a number of occasions that he is going to die. Amy is threatened with death a couple of times. Though Eggman never actually uses it, carrying that big pistol about in a couple of the cutscenes certainly shows that he means SeriousBusiness. There's even a level called "Death Chamber" and the music used for the level constantly repeats those words. Even more blatant, [[spoiler:Gerald specifically mentions the death of his young granddaughter at the hands of GUN. He also talks about a "death sentence for every human being on Earth".]]
* NewPowersAsThePlotDemands:
** While Sonic uses the term "warp" to describe Shadow's first use of Chaos Control, the way it's presented in the cutscene suggests Chaos Control is being used so TimeStandsStill, freezing Sonic in place as Shadow rushes past, which is consistent with how Shadow's "Chaos Control" works in multiplayer. [[spoiler:During the AstralFinale, Sonic instead successfully attempts to use Chaos Control to {{teleport|ation}} from one enclosed space to another]].
** Despite Shadow introducing the Chaos Control concept while in possession of the green Chaos Emerald, [[spoiler:he's able to use Chaos Control during the FinalBoss battle despite having no emerald in his possession--Sonic has the fake emerald, while the real emerald is still in the control room with Tails and Eggman[[note]]The Dark Side story indicates that he can use Chaos Control while in range of other Chaos Emeralds--that's how he rescues Rouge--but the Chaos Control mechanic for the FinalBoss is triggered by becoming too distant, which would imply he's ''not'' in range and thus not using the same technique he used to rescue Rouge[[/note]]]].
* NewRulesAsThePlotDemands: Shadow's IncomingHam EstablishingCharacterMoment is as much about introducing the fact that the Chaos Emeralds can now be used individually ''via'' Chaos Control as it is about introducing Shadow.
* NiceJobBreakingItHero: Tails gets manipulated by Eggman into revealing that the Chaos Emerald Sonic was going to trade for Amy was a fake, leading to Sonic's near death.
* NintendoHard:
** Every 5th mission for a level has a Hard mode challenge, where the level's difficulty borders on downright frustrating. Many consider Eternal Engine, Crazy Gadget, Mad Space, and Cannon's Core to be punishingly difficult already. [[OhCrap Then you find out that even]] ''[[ThatOneLevel they]]'' [[OhCrap have Hard Modes themselves...]]
** Getting A-Ranks on the early Action and Shooting stages aren't ''too'' obscenely hard, but roughly halfway through the game they become incredibly annoying without resorting to SequenceBreaking shortcuts to get massive time bonuses. And let's not even talk about the Hunting Stages, the system for which has been tweaked to be ''even more annoying''.
* NoCanonForTheWicked: Zigzagged. The Hero and Dark stories happen at the same time, with the only variance between the two being who wins the boss fights that pit playable characters against each other. The Last story is equally led into by both. [[spoiler:No matter who wins the Tails/Eggman and Sonic/Shadow fights, Eggman winds up with the last emerald (he's even seen grabbing it in the hero side ending) but the Eclipse Cannon is prevented from firing (as indicated by a warning light).]]
* NoCommunitiesWereHarmed: The nation's capital is based on UsefulNotes/SanFrancisco, where Creator/SonicTeam was based at the time. Route 101, Route 280, and Mission Street all reference major roadways in the city. The ''VideoGame/SambaDeAmigo'' references in Mission Street may serve as a dual reference to the Mission District, which was (and is still somewhat) largely Hispanic. Shadow's Radical Highway level is also based on the Golden Gate Bridge.
* NoConservationOfEnergy: When Sonic and Shadow use Chaos Control to stop the falling ARK, the colony comes to a complete halt. The explosion of light was no where near big enough to be equal to its previous momentum. Of course, SEGA has never bothered to explain exactly ''how'' Chaos Control works, [[AWizardDidIt so... ]]
* NoEndorHolocaust:
** ''VideoGame/Sonic3AndKnuckles'' establishes that the Master Emerald is needed for Angel Island to float, and ''VideoGame/SonicAdventure'' is very, very clear that if anything goes wrong with the Master Emerald [[ColonyDrop the island will land like a sack of bricks]], but ''Adventure 2'' distinctly ignores the fate of Angel Island while Knuckles and Rouge are competing for the Master Emerald pieces, presumably to better sell them acting LikeAnOldMarriedCouple when Knuckles should rightly be furious.
** Both {{Boss Battle}}s shared by Tails and Eggman take place when Amy Rose is technically in the immediate vicinity, but despite the repeat BeamSpam, MacrossMissileMassacre, and occasional WaveMotionGun, Amy's just fine. The rematch during the AstralFinale is a particular offender, given that there are enormous canisters of explosive chemicals nearby and the panes of glass facing outer space imply the room is especially fragile, but, nope, that room is MadeOfIndestructium.
* NonDubbedGrunts: Zig-zagged. They dubbed them...by having the English voice actors repeat the ''Japanese'' phrases. This is particularly noticeable with Eggman, who says things like "Yosh..." and "Hori!" even though it's Deem Brimstow saying it.
* NoOSHACompliance:
** In "City Escape", who decided it was a good idea to put a giant loop de loop with speed boosters that sends you hurling down a tall building in a public park area?!
** Prison Island wouldn't pass OSHA standards either, most egregiously with the giant pit surrounding the area Rouge fights a G.U.N. robot in.
** OSHA would've had a fit if they set foot on the Space Colony ARK--the entire station is a giant death trap, most egregiously with its fragile air locks throughout the hallways.
* NoSidepathsNoExplorationNoFreedom: ''Adventure 2'' does away with Adventure fields and the ability to select characters, instead having the player experience every gameplay style in the same story, with stages coming one after another in sequence. Upgrades are found within the stages as well.
* NonstandardGameOver: Take too long to defeat the Final Hazard, and it will breach the earth's atmosphere and kill everyone.
* NostalgiaLevel: Collecting all 180 Emblems rewards you with a 3D version of GreenHillZone from the original ''VideoGame/{{Sonic the Hedgehog|1}}''.
* NotBad: In the Hero Story in the first Sonic/Shadow boss battle, Shadow, who is defeated, says this to Sonic that he wasn't bad for an impostor.
* NotMeThisTime: At the start of the Last Story, Knuckles wrongly accuses Eggman of [[spoiler:sending the ARK on a crash course to earth.]]
-->'''Eggman:''' I'd have done this a long time ago if I had the chance!
* OffscreenMomentOfAwesome: Amy Rose, who spends the game as a NonActionGuy, is introduced on Prison Island after having somehow gotten there entirely on her own (Tails, by comparison, had to fly his CoolPlane to get there). She's also the one to bust Sonic out of prison with a stolen key card that she's gotten her hands on, somehow.
* OhCrap:
** Sonic's reaction when Eggman traps him in the capsule pod rigged with explosives. This is also his reaction when the Egg Golem appears.
** Tails' reaction when he realized that Eggman tricked him into [[YouJustToldMe revealing the Emerald was fake]].
** Knuckles' reaction when he gets caught by King Boom Boo in Death Chamber.
** Amy's reaction when Eggman confronts her in the ARK while pointing a gun at her.
* OmnicidalManiac: [[spoiler:Gerald did ''not'' take Maria's death well. His plan involved crashing the ARK into the Earth to wipe out humanity for the sake of vengeance.]]
* OnceMoreWithClarity: [[spoiler:Shadow's flashback to Maria's dying moments in the Last Story plays out like it did the first time, but reveals that all Maria wanted was for the people of earth to be happy, not to see them all die like Shadow originally thought.]]
* OneWingedAngel: [[spoiler:The Biolizard becomes Finalhazard when he fuses himself with Space Colony ARK.]]
* OnSiteProcurement: Each of the six player characters has a power-up tucked away in each of their standard levels (''i.e.'' not the racing levels or Cannon's Core). Some are necessary for level completion, while others are necessary only to complete special missions. Because the number of levels is uneven, some of the characters will have an advantage over their rival; these extras are unnecessary, but make things easier.
* OnTheNext: After beating one of the two main stories, a trailer plays for the other one. After beating both of them, a trailer plays for the Last story.
* OpenSecret: Some of the characters gathered intel on Prison Island, a top secret military prison from a public news broadcast.
* OutGambitted:
** Sonic and Tails plot to give Eggman a fake Emerald that will explode when it's put into the Eclipse Cannon, thus making it unusable. Immediately detecting a spare Emerald signature, Eggman seals Sonic inside a rocket, causes Tails to accidentally spill the beans, and shoots Sonic out of the ARK to a most certain death.
** The endgame is caused by this. In the Dark Story finale, Eggman is defeated, but he still is able to get the yellow Chaos Emerald and hooks it up to the Eclipse Cannon, allowing him to use it again and again. What he didn't know was that doing so ended up activating Gerald's giant middle finger to the world.
* OverlyGenerousTimeLimit: White Jungle has a time limit of ten minutes that Shadow has to complete the level before the bomb explodes, taking Rouge and the Chaos Emeralds with it. Even when stopping to check for secrets and explore a few nooks and crannies, it's quite easy to reach the goal with more than half the timer remaining.
* PainfulRhyme: [[{{Enforced}} Due to Hunnid-P having only one day to write and record all the music for Knuckles' levels,]] the rap features a great deal of twisted pronunciation, like forcing "Emeralds" to rhyme with "lose".
* PainfullySlowProjectile: The GUN MechaMooks shoot extremely slow-moving shots that even Eggman could probably dodge while rolling out of bed, let alone Sonic. Certain GUN Hunters (designated "Gum Hunters") do attempt to fire blue projectiles that bind the player, but aren't any faster than the normal yellow ones.
** The E-1000 series robots share this issue too, but (very slightly) make up for it by firing two shots in tandem from their dual laser cannons.
** Averted in the Hard Mode versions of the levels. The enemies will fire shots that move faster than in normal difficulty, though you can still dodge them if you're quick enough.
* PapaWolf: Gerald loved his granddaughter Maria, [[spoiler:[[KnightTemplar and once she was killed, he almost destroyed the world.]]]]
* ThePasswordIsAlwaysSwordfish: The code to access Project Shadow and to fire the [[KillSat Eclipse Cannon]] is "Maria".
* PathOfGreatestResistance: Because Sonic and Shadow can use the Homing Attack, which was introduced in [[Videogame/SonicAdventure the previous game]], this game has paths identifiable (and accessible) only by finding a trail of stationary enemies. This is most commonly used to begin an expert path or for a shortcut; there are only two levels where this is actually required (excluding hard mode): Metal Harbor and Crazy Gadget.
* PerpetualMotionMachine: The eternal engine developed by the ARK appears to be one, provide that it's ExactlyWhatItSaysOnTheTin.
* PlotArmor: [[spoiler:Because Sonic is the hero and obviously can't be permanently killed off, he's given a ''very'' contrived way of surviving getting jettisoned into space ala an explosive rigged escape pod by Eggman--he had a fake Chaos Emerald with him and was somehow able to use Chaos Control with it to teleport away. Even Sonic admits he has no idea how he was able to pull it off.]]
* PlotHole:
** During the SecretFinalCampaign, [[spoiler:it's revealed that Gerald Robotnik went mad and became a MisanthropeSupreme after being taken into GUN custody, which raises the question of how he was able to program the Ark and the Biolizard still aboard to carry out his revenge while still in GUN Custody.]]
** The motives of Rouge the Bat[[spoiler:'s client]] are not explained.
* PoliceAreUseless: Even ''Sonic'' lampshades how GUN can't keep him contained.
* PosthumousCharacter: Both Gerald and Maria Robotnik have been dead for 50 years, but Gerald's inventions and Maria's relationship with Shadow are extremely important to the plot. [[spoiler:Gerald is also the real villain, as he made sure Shadow would have the earth destroyed as revenge for Maria's death.]]
* PowerStrainBlackout: [[spoiler:Sonic nearly suffers one as a result of the aforementioned PowerCopying.]]
* PowerupLetdown: The Mystic Melody power-up is unique in the fact that everyone can obtain it, is only found at the end of very convoluted or out of the way detours, and allows you to interact with ancient ruins. However, while it will on occasion do something of note like generating a portal or rings, far and away its main use is to open doors or paths that hidden Chao are hiding behind, limiting its actual utility to Find the Chao missions. Investigating the melody-locked areas outside of Chao missions will only give you a OneUp.
* PreFinalBoss: The Biolizard is fought just before you face him again as [[TrueFinalBoss The Final Hazard]].
* PreRenderedGraphics: The scene of the Tornado escaping from the exploding Prison Island used a pre-rendered video of the island blowing up, and the Tornado was a real-time 3D model placed in front of the video. The cutscenes of the Eclipse Cannon firing at the moon, Sonic and co. taking the shuttle to the ARK, and about half of the cutscenes in the Last Story are also all pre-rendered, as are the opening cutscenes before the title screen — both the logo splash screen on the original Dreamcast version and the extended opening cutscene on ''Sonic Adventure 2 Battle''.
* PreviouslyOn: Upon continuing a story segment, the character that you're about to play as will give a brief summary of what's happened up to that point and what they're about to do. For the Last Story, Amy narrates for the Cannon's Core stage.
* PrisonLevel: The third level in the Hero Story called "Prison Lane" has Tails break into a GUN prison on an island to rescue Sonic, who was mistaken for Shadow. The levels features robot guards that Tails has to blast through in his Tornado in order for the iron bars to open.
* ProductPlacement:
** Due to Sonic now wearing Soap Shoes, ads for them are all over the game. They were removed from the HD releases since Soap Shoes went out of business in the interim.
** In ''Battle'', there were ads for ''[[VideoGame/PhantasyStarOnline Phantasy Star Online Ep. I & II]]'' which was released around the time of ''Battle''. Oddly these ads remained in the HD release, despite the game being discontinued.
* PromotedToPlayable:
** Eggman is playable for the Dark Story Shooting stages.
** Inverted for Amy who is reduced to an NPC in the original Dreamcast release. She is playable in ''Battle'', though.
* PropRecycling: If you look closely, you can notice that the back of the GUN truck in City Escape is a super-sized metal crate.
* PsychoPrototype: [[spoiler:The Biolizard as the prototype of Shadow. It has the mind of an animal and, [[AllThereInTheManual according to supplementary material]], its dangerous behavior was the reason why G.U.N. decided to have the ARK shut down 50 years before the events of the game.]]
* PsychopathicManchild: Though in one of his more composed forms here, Eggman still obviously gets in the odd moment of childlike grouchiness. He commits to some outright TantrumThrowing when the Eclipse Cannon's first run doesn't go as powerfully as hoped, which an amused Rouge mocks him over.
-->'''Rouge:''' Look at you. Throwing a tantrum. Like a little kid! How totally embarrassing!
-->'''Eggman:''' Don't forget ''your'' end of the bargain, Bat-girl! ''Where's my emerald?''
* PumpkinPerson: You can give Chao pumpkins to wear on their heads.
* PunctuatedForEmphasis: Eggman when you get an A-Rank.
-->"NOW YOU KNOW WHY I! AM! THE BEST!"
[[/folder]]

[[folder:Q-Z]]
* QuicksandSucks: In Tails' Hidden Base and Eggman's Sand Ocean levels. Quicksand is usually no problem, but since they're piloting walking mechs, it functions like a {{Bottomless Pit|s}}, meaning they lose a life if they fall in.
** In Sonic's boss fight with the Egg Golem, he can easily jump out of the sand if the player spams the jump button.
** Interestingly, in Hidden Base, there's a specific shifting platform that raises and lowers just enough for the player to start sinking in quicksand only to seemingly be pushed back out to safety. However, Tails will still die in mid-air as the programmers likely never expected a player to escape the quicksand in a mech stage.
* RashomonStyle: As with the [[VideoGame/SonicAdventure previous game]], it's debatable who won the character-on-character boss fights. Most of the cutscenes treat them as stalemates anyway, with two important exceptions being the final battles between Eggman and Tails and Sonic and Shadow. The endings of the Dark and Hero pathways contradict each other as a result, but both of them plausibly set up the Last Story.
** [[spoiler: In the Hero storyline, Tails defeats Eggman in revenge for Sonic's apparent death, while Sonic sends Shadow off to lick his wounds. Eggman still manages to sneak away with the last Chaos Emerald and place it into the cannon's console off-screen, but Sonic destroys the cannon before it can fire. Success! Right?]]
** [[spoiler: In the Dark storyline, Eggman defeats Tails, Shadow prevents Sonic from reaching the Eclipse Cannon, and Eggman's plan goes off without a hitch! So what's with the siren?]]
* ReactorBoss: EternalEngine, in which Tails fights the ARK's power generator.
* RecurringRiff: The game's main theme, ''Live & Learn'', has its opening riff incorporated into several tracks in the game, such as the menu tracks and many others.
* RecycledPlot: This game reuses quite a few elements from the original ''VideoGame/SonicAdventure''. Eggman takes on a new character as TheDragon in yet another plan for world domination[[note]]Chaos in the first game, Shadow in the second[[/note]]; this newcomer turns out to be a DragonWithAnAgenda who plans to take {{Revenge}} on the world because his enemies killed those who the newcomer cared about in the past[[note]]The chao for Chaos, Maria for Shadow[[/note]]. There's even a new girl with a connection to Knuckles, who the story uses to explore the newcomer's motives[[note]]Tikal in the first game, Rouge in the second[[/note]].
* RedemptionEqualsDeath: [[spoiler:Shadow originally died after falling from the ARK into the atmosphere. Later {{retcon}}ned.]]
* RedOnesGoFaster:
** Tails's unlockable multiplayer reskin takes his Cyclone mech and repaints it to look like his original plane, the Tornado, which is primarily red. In addition to the sweet paintjob, it runs at a speed that rivals the Cyclone's car form.
** The [[UniqueEnemy very rare]] [[http://info.sonicretro.org/Phoenix_(robot) Phoenix]] enemy is a red model in the fairly common bomb-throwing [[http://info.sonicretro.org/Hornet_series Hornet series of robots]], and it outpaces the regular models easily.
* RememberTheNewGuy:
** This game abruptly introduces the government force of G.U.N. into the series, whose presence is a strong contrast in tone to the previous games, and they weren't even acknowledged or foreshadowed in previous installments.
** Ditto for Rouge the Bat, whose first cutscene isn't really introductory the way Shadow's is. You may well have thought she was an already established character. Lightly corrected with Knuckles's PreviouslyOn recap for the Wild Canyon stage--Knuckles and Rouge were fighting in the desert because Rouge had stolen the Emerald and he had finally tracked her down.
* RemixedLevel:
** Inverted; instead of revisiting the same level with modifications, ''Adventure 2'' has groups of stages that share specific assets to establish they're all part of the same setting. Shared-setting stages are all clustered together on the stage select map.
*** Sonic's Green Forest and Shadow's White Jungle are both set within the forest on the west side of Prison Island.
*** Knuckles' Pumpkin Hill stage and Shadow's Sky Rail are set within the same canyon surrounded by jack-o-lantern mountains.
*** Rouge's Security Hall, Tails's Prison Lane, and Eggman's Iron Gate are all set within the GUN base itself on the east side of Prison Island.
*** Sonic's Metal Harbor and Eggman's Weapon Bed are set on the exterior part of the base east of the island.
*** Tails' Hidden Base and Eggman's Sand Ocean stages both take place in the desert outside of Eggman's hidden base. Knuckles's and Rouge's first cutscene occurs somewhere in the Hidden Base stage.
*** Rouge's Egg Quarters, Sonic's Pyramid Cave, Knuckles' Death Chamber are both set within Eggman's base itself. The Egg Golem BossBattle also occurs within the base.
*** Tails' Route 101 and Rouge's Route 280 both take place on the same stretch of highways.
*** Sonic's City Escape is set entirely within a city, while Shadow's Radical Highway is set on highways outside the main urban center; Tails's Mission Street transitions between the two settings. Sonic's fight with the Big Foot mech takes place in a city plaza at night.
*** Eggman's Cosmic Wall, Sonic's Final Rush, Shadow's Final Chase, Rouge's Mad Space, and Knuckles' Meteor Herd levels all take place in the [[AstralFinale not-quite-airspace]] outside the Space Colony ARK.
*** And lastly, Eggman's Lost Colony, Tails's EternalEngine, Sonic's Crazy Gadget, and the Cannon's Core stages are all set within the ARK itself.
** Played straight with Knuckles' Wild Canyon and Rouge's Dry Lagoon stage--each level is identical in layout save for some scenery changes (Dry Lagoon has water and more vegetation, Wild Canyon has more rocks and sand) and how each character transitions between the two halves of each level. The multiplayer versions of these levels elaborate further, with the multiplayer Wild Canyon being set at twilight and the multiplayer Dry Lagoon taking place at night.
** The first Tails and Eggman BossBattle takes place on one of the hangar platforms from the Metal Harbor or Weapons Bed stages, ringed with road blocks to fence you in.
** The Flying Dog and Big Shot {{Boss Battle}}s appear to take place in the same room, but the Flying Dog version has large steel fences that Rouge can climb.
** Sonic's and Shadow's first battle takes place on a unique platform arena somewhere in the Green Forest stage.
** The King Boom Boo BossBattle takes place near the E-01 central engine in the Pyramid Core section of the Death Chamber stage.
** Both Sonic and Eggman must fight the Egg Golem, but Eggman's fight takes place after Sonic's, so the main ring of the arena in Eggman's fight is already busted up and the sand below littered with platforms that he can jump and hover between.
** Knuckles' and Rouge's BossBattle takes place above a remixed version of the mining shaft in Meteor Herd, which suddenly has inexplicable upward gusts of heat when it opens that it doesn't have in the Meteor Herd stage itself.
** The Downtown Race mini-stage in the Action Race multiplayer is the "snowboard" section at the start of City Escape remixed into an actual snowboard race with actual snow.
* ReportsOfMyDeathWereGreatlyExaggerated: Sonic is presumed dead after [[spoiler: the capsule that Eggman traps him in and launches into space explodes. Of course, Sonic survives, but Amy, Tails, Eggman, and Shadow are convinced that he's truly gone]]. The last part of both stories involves Sonic making a mad dash to the Eclipse Cannon, with both sides believing he perished in the explosion . The only exceptions are Knuckles and Rouge, who were off doing their own thing, and weren't around to see what happened.
** Downplayed in the Last Story, where Eggman admits he wasn't really convinced about [[spoiler: Sonic's "death"]] in the first place, and states he should have known better than to expect that that would be it.
* RestoredMyFaithInHumanity: Shadow, thanks to Amy's speech. [[spoiler:Though it helps that Shadow remembered that Maria told him to help humans, not eliminate them.]]
* ReversePolarity: The Chaos Emerald Tails provides to Sonic once aboard the ARK has the power to "reverse the energy field" of the gathered emeralds and cause an explosion. [[spoiler:This is because that particular emerald is fake]].
* RidiculouslyCuteCritter: The Chao return from ''VideoGame/SonicAdventure''. This time, they're cute enough to star in their own movies in-universe.
* RightHandVersusLeftHand: Despite the Guardian Unit of Nations being implied by the name alone to be an ally of the United Federation, [[spoiler:the President of the United Federation and his Secretary have hired Rouge to conduct their own private investigation of Project Shadow.]]
* TheRival: Sonic/Shadow, Tails/Eggman, and Knuckles/Rouge.
* RivalsTeamUp: [[spoiler:All of the Hero and Dark characters team up in the final stage Cannon's Core to stop the Eclipse Cannon. In order, Tails, Eggman, Rouge, Knuckles, and Sonic complete the level, with Shadow taking on the boss. Then in the final boss, Sonic and Shadow (who had a HeelFaceTurn) turn into their super forms to fight the Finalhazard, Biolizard fused with the ARK.]]
* RousseauWasRight: Core part of Amy's philosophy. It's what caused Shadow to back down on his revenge against the world.
* RuleOfCool: Shadow's EstablishingCharacterMoment features him as an IncomingHam MilkingTheGiantCow {{Atop A Mountain Of|Corpses}} HumongousMecha, and because TalkingIsAFreeAction, Shadow ends with a VillainExitStageLeft right when GUN catches up with Sonic. After this one scene, however, Shadow never again displays this level of theatrics (and no reason for Shadow to make this speech is given in the first place), so its main contribution is to be a cool way to show off the new character.
* RuleOfDrama: The game excuses Sonic's CutsceneIncompetence being captured by G.U.N. near the start of the story by having him claim he let it happen so he could look for clues--which is really just an excuse[[note]]At no point is Sonic told that he's being taken to Prison Island or that there will be clues there, he ignores the one [[{{Foreshadowing}} very big clue]] in his own jail cell that something is going on, and by all appearances he can't do anything in his holding cell until Amy busts him out.[[/note]] for Sonic to already be on Prison Island when Eggman, Shadow, and Rouge are making their big raid so he can find and fight Shadow.
* RuleOfThree:
** Each team has three members. The Hero team has Sonic, Tails, and Knuckles, and the Dark team has Shadow, Rouge, and Dr. Eggman.
** The members of each team are organized into three pairs of rivals: Sonic and Shadow, Eggman and Tails, and Knuckles and Rouge. Each pair of characters has its own style of gameplay.
** The goal of Knuckles and Rouge's stages is to find three objects of a certain type.
** Knuckles and Rouge can consult the hint monitors in each stage up to three times per each object.
** There are three storylines in the game; Hero, Dark, and Last.
** GUN has three HumongousMecha, the Big Foot, Hot Shot, and Flying Dog.
** Most playable characters have three {{Limit Break}}s in multiplayer (excepting Metal Sonic, who has none, and the unlockable {{Palette Swap}}s, which usually have only one of the LimitBreak from the set of three).
** There are three Chao Gardens, each corresponding to the Neutral, Hero, and Dark types of Chao.
* RunningGag: Sonic and Tails creating plans then leaving Amy behind, followed by her complaining about it. It happens no less than ''five times'' throughout the game, and they pay the price for it when Eggman finds Amy and holds her at gunpoint to trick the two into revealing the deception with the fake chaos emerald.
* SadisticChoice: Invoked by Eggman near the end of both the Hero and Dark stories: [[spoiler:Eggman has Amy held hostage and lures Sonic to him, threatening to kill her unless Sonic relinquished the last Chaos Emerald needed to power the Eclipse Cannon. Sonic, having a fake Emerald designed to destroy the cannon, acquiesces to Eggman's demand. Unfortunately, [[HoistByHisOwnPetard Eggman already knew the Emerald was fake and had a trap set up for Sonic...]]]]
* SanitySlippage: Gerald Robotnik, as his diary indicates, definitely went through one after Maria died; ''I became scared as I could no longer control my thoughts... All I knew was that I wanted it to end...''
* SarcasticDevotee: Even if [[spoiler:she was a double agent]], Rouge poses as one to Eggman, especially when she mocks him for throwing a tantrum when Sonic interrupted his conversation with the President through the screen.
* SaveTheVillain: After their BossBattle, Knuckles saves Rouge from falling down into a pit of lava, despite the fact that she tried to steal the Master Emerald. They AlmostKiss.
* SavvyGuyEnergeticGirl: Knuckles and Rouge. During their introductory cutscene, after Knuckles shatters the Master Emerald to keep it out of Eggman's clutches, Rouge panics, seizes him by the throat, and throttles him until he calmly explains himself.
* SayMyName:
** Shadow yells out "Maria" when losing a life in levels. Also does this a lot of time during his flashbacks.
** Amy and Tails both do this separately when Sonic exploded in the capsule. [[spoiler:Or so they thought; Sonic manages to escape using the fake Emerald.]]
** Tails mutters "Sonic..." whenever he dies in a level. He shouts it instead if he falls down a bottomless pit.
* SchizophrenicDifficulty: Since you jump around from playing style to playing style, this can be in effect if you are much better at some characters than others.
** Also, each stage has the same five missions in the same order. Depending on which character you are using, some of the missions will be easier or harder than usual. Tails and Eggman's stages have very few rings and LOTS of enemies, so the second mission, 'Collect 100 Rings!', is harder for them than it would be for other characters. The timed missions for Knuckles and Rouge tend to be harder than their 'Complete Hard Mode' missions since for them, while the emeralds are in very annoying and hard to reach places in Hard Mode, they're in the same place each time.
* ScrewThisImOuttaHere: After a handful of Master Emerald shards are lost during the approach to the ARK, Knuckles leaves Sonic and the others in the space shuttle to find them, with Tails lampshading that he bailed. After he successfully restores the emerald, he tries to reconnect with the others and finds Sonic, who asks him to look after Tails and Amy.
* SealedBadassInACan: Shadow, who can fearlessly hold his own in the face of adversity, capable of harnessing the power of Chaos Control, and rivals Sonic's running speed.
* SecondHourSuperpower: Applies to certain upgrades that all of the characters receive early on, which grant abilities that become essential game mechanics throughout the rest of the game. It can be weird starting a new save file after playing on an old one for a while and realizing that these abilities aren't available from the very start of the game.
** Sonic and Shadow get Light Dash shoes.
** Tails and Eggman get Hovering boosters.
** Knuckles and Rouge get digging tools.
** Every character gets an upgrade that lets them break through iron crates.
* SecretAIMoves:
** In the AstralFinale {{Boss Battle}}s against rival characters, TheRival can use {{Special Attack}}s that the player can only use in multiplayer (Shadow's Chaos Spear, Rouge's Black Wave, etc).
** In Sonic's and Shadow's FinalBoss battle, the boss uses a unique version of Chaos Control or Time Stop; TimeStandsStill when using the multiplayer version of these special attacks, but in the story the boss uses it to {{Teleport|ation}} in front of the player character if they fall behind in the race.
* SecretCharacter:
** In the Dreamcast version, getting all A ranks in a certain playable character's missions sees a member of the original ''VideoGame/SonicAdventure'' cast PromotedToPlayable in the 2P Battle Mode--Amy for Sonic, Metal Sonic for Shadow, Tikal for Knuckles, Chaos 0 for Rouge, Chao Walker for Tails, and Big the Cat for Eggman. These appearances are just reskins and have no effect on gameplay.
** The [=GameCube=] version and its subsequent ports (with the Battle DLC) have all of the extra characters available right from the start (except for Big the Cat, who was replaced with the Dark Chao Walker), gives them a full set of unique animations, gives them unique stats to better differentiate them, and allows for players to compete with any characters in the same category, instead of only allowing Hero vs. Dark. A complete set of A ranks now unlocks alternate multiplayer skins for the 6 main characters instead, with those new skins ''also'' giving unique stats.
** In the UpdatedReRelease for the Gamecube, each playable character has a menu theme that can be selected, which will alter the voiceover and background of the main menu system. Secret themes for Amy, Omochao, and Maria can be purchased from the Black Market in the Chao Kindergarten, and a fourth secret theme for the president's secretary can be unlocked at theme select screen itself ''via'' ClassicCheatCode.
* SecretFinalCampaign: Complete both the Hero and the Dark stories, and one final story that has you playing both factions becomes available.
* {{Sentai}}: The Chao Rangers of the Challenge Races, a team of five highly-trained Chao who come in the colors Red, Green, Pink, Blue, and Yellow. Red is a JackOfAllStats, while the remaining four each specialize in different stats.
* SerialEscalation: The special LightningBruiser gold and silver rival Chao from ''VideoGame/SonicAdventure'''s Chao Race return in the Chao Race of SA 2... as [[SoLastSeason the earliest, most basic Challenge race]]. There are eleven more races after them, each increasing in difficulty.
* SexySecretary: The president's secretary, who comprehensively lays out the disastrous effects of the ARK's Eclipse Cannon for him and manages conferences between them and their agent. It's hard to tell with the graphics, but her suit has a plunging neckline.
* ShiftingSandLand: All of the stages surrounding and inside Eggman's [[BuildLikeAnEgyptian pyramid base]].
* ShonenDemographic: Moreso than [[VideoGame/SonicAdventure the first game]]. The more darker, more action-oriented plot with some standard shounen anime elements (e.g. [[DarkAndTroubledPast Shadow's tragic backstory]], and the military vs. the cocky teenaged hero and his friends in a potentially world-ending battle) is one reason it's considered to be the most "anime"-esque of all Sonic games (minus [[VideoGame/SonicTheHedgehog2006 one other glaring exception]]).
* ShoutOut:
** There are also a couple references to ''VideoGame/PhantasyStarOnline''. [[RandomlyDrops Random Drop]] boxes can be found in space stages. Some unlockable alternate costumes on the [=GameCube=] version are similar to what the characters in said game wear, and there are billboards advertising it scattered throughout the city levels.
** During the famous scene of Eggman's video-message to the world, the mixture of Japanese and English text behind him is awfully reminiscent of [[Anime/DigimonAdventure Digivolutions.]]
** The entire final sequence where Sonic and Shadow [[spoiler:use Chaos Control to push ARK back into orbit]] is a reference to the climax of ''Anime/MobileSuitGundamCharsCounterattack''.
** Some of the Achievements/Trophies for the HD remake are this. [[VideoGame/GuiltyGear Heaven Or Hell]] & ''VideoGame/BeyondGoodAndEvil'' mainly.
** ''Sonic Adventure 2'' writer Shiro Maekawa stated in a [[https://ykz-sonic.blogspot.com/2006/09/shiro-maekawa-interview-adventure-2-sonic-channel.html interview]] that the scene with Shadow and Maria views the Earth from Space Colony ARK was influenced by ''Manga/PleaseSaveMyEarth''.
** The ghost enemies are called [[Franchise/SuperMarioBros Boos]].
** In Knuckles' monologue narration recap in the Hero's Story, before he enters the Aquatic Mine and Pumpkin Hill, he says "Sure feels creepy, [[Franchise/GhostBusters but I'm not afraid of ghosts!]]".
** A poster that reads "Planet of the Chaos" can be found throughout City Escape and the BigFoot boss fight, which is a tribute to ''Franchise/PlanetOfTheApes''. The Creator/TimBurton [[Film/PlanetOfTheApes2001 remake of that film]] was released a month after this game.
** In Crazy Gadget, the large colored platforms surrounding the Goal Ring resemble [[VideoGame/{{Tetris}} tetrominoes]]. If you take Omochao to the Goal Ring, he will comment "Hmmm. This looks like a game I've seen before."
* SkewedPriorities: Knuckles' single-minded devotion to the Master Emerald becomes an issue once he joins up with Sonic and friends.
** When the heroes enter Eggman's pyramid base, Knuckles prioritizes finding Rouge over stopping a possible world ending scheme.
--->'''Knuckles''': I saw Eggman go inside the pyramid, and, ''more importantly'', I saw that bat girl go inside with him as well.
** When the space shuttle the heroes are all on is damaged ''en route'' to the space colony, some of the Master Emerald shards are ripped out of the hatch. Knuckles (albeit understandably panicking) immediately seizes control of the space shuttle and causes it to spin even further out of control.
* SkyBox: The levels look like they occur in the real world, but there are glitches that allow the user to jump out of a level. Doing so reveals that the levels are hallways built in one large skybox.
* SkyHeist: Knuckles and Rouge's introductory cutscene (which is shared in both the Hero and Dark storylines) depicts Dr. Eggman attempting to steal the Master Emerald with the claw of his Eggmobile and take it back to his base. Knuckles jumps into the air and breaks the Master Emerald, apparently [[VideoGame/Sonic3AndKnuckles not wanting to get electrocuted again]]. Rouge is shocked when she sees this happen, but Knuckles tells her that if the Emerald is in pieces, he can restore it once he finds them all.
* SlapSlapKiss: While it's [[AlmostKiss not quite Kiss]], Knuckles and Rouge literally have this going on after the former saved her life.
* SlasherSmile: The boos in the haunted stages have a scary, fanged-toothed smile.
* SlidingScaleOfLinearityVsOpenness: The main game is level 3. There are multiple paths through each level, with more being unlocked as you gain more items, and you can replay levels with different goals for more emblems. The chao raising mini-game, though, is decidedly level 6, for the game gives you no overall goal to accomplish in raising your chao.
* TheSmurfettePrinciple: Rouge is the only female character of the main 6 playable characters.
* SoundtrackDissonance: The themes for all of his stages seem to imply that [[ProudWarriorRaceGuy Knuckles]] is gangsta.
* SpearCarrier: The president's secretary, who has a few lines at the start and end of the scene where Sonic and Tails crash the president's meeting with Dr. Eggman... and also, for some reason, [[SecretCharacter her own unlockable menu theme]].
* StayInTheKitchen: Twice, Sonic and Tails go running off into action and leave Amy behind, despite Amy being competent enough to do things like get to Prison Island and secure a card key to Sonic's cell on her own. Amy gets mad each time.
** Tails abandons Amy with Knuckles once he and Sonic make plans to intercept Eggman's conference with the president.
** On the ARK, where Tails and Sonic out-and-out ignore Amy's presence while making plans to raid the cannon's core and abdandon her when their plans are made. They pay for it this time when Eggman takes her hostage.
-->'''Amy:''' ''I hate you! [[LampshadeHanging You guys always leave me behind]] and have all the fun!''
* StepfordSmiler: [[spoiler:In the end of the Last Story, Sonic is noticeably grieved of Shadow's sacrifice, and when Amy goes to ask what's wrong with him, he assures that it's nothing and cheerfully informs her that it's time to head back to the earth. As everyone left the ARK, Sonic turns back, waving goodbye to the fallen Shadow in a pensive and solemn tone.]]
* TheStinger: Of two kinds:
** Complete either the Hero or Dark Story, and a cinematic preview for the other will play after the credits. Complete both, and a preview for the Last Story will play instead.
** After the Last Story credits, some text appears on the screen: "A new day brings new adventure. But for now... rest easy, heroes." This is followed by one last shot of Shadow.
* StorefrontTelevisionDisplay: One briefly shows up during the cutscene where Eggman demonstrates the Eclipse Cannon, with all of its [=TVs=] displaying his message while several passersby watch on in horror.
* StormingTheCastle: {{Exaggerated}}. Sonic and Tails raid Eggman's pyramid base to find the means to raid the Space Colony ARK so they can wreck the eclipse cannon and prevent it from being fired a second time.
* StoryArc: This is the first game in the ''Sonic'' series to deal with the story of Shadow. It was later continued in ''VideoGame/SonicHeroes'' and finished in ''VideoGame/ShadowTheHedgehog''.
* {{Stripperiffic}}: Rouge's unlockable PaletteSwap for the multiplayer in ''Battle'' makes her look like [[http://images3.wikia.nocookie.net/sonic/images/4/41/Rouge_18.png she's going clubbing if not streetwalking]].
* SugarBowl: All of the Chao Gardens, where the most pressing issue is an empty stomach; even the Dark Garden, which looks like a haunted graveyard and has a pool of red liquid that may or may not be blood, is a pretty safe place for your cute little guys to reside.
* SuperMode: Super Sonic, of course, but Super Shadow as well.
* SupermodelStrut: Rouge, to the point that when she runs, she ''keeps sashaying.''
* SuperMovePortraitAttack: The multiplayer attacks have the character's image pop in with a short animation before the attack is fired off. This is retained in the Hero/Dark counterpart boss fights when the enemy uses them.
* SuperNotDrowningSkills: Once Knuckles gets the Air Necklace upgrade in Aquatic Mine, he can breathe underwater indefinitely. This is especially useful for his section in the true final action stage, Cannon's Core, a majority of which takes place underwater.
* SuspiciouslySpecificDenial: In Mad Space, the hints are reversed: for the third hint, this usually manifests as the hint telling you ''not'' to go to a certain place and/or ''not'' to perform a certain action there.
* TakeItToTheBridge:
** Knuckles and Rouge have their final confrontation during the AstralFinale on a crossbeam overlooking a magma pit--Rouge even [[DisneyVillainDeath almost falls off]] in the following cutscene. This is also where Rouge finally gives up the emerald and gains a new appreciation for Knuckles.
** Sonic's and Shadow's final battle takes place on a long track through space.
* TakeMyHand: Rouge makes a misstep in Meteor Herd (wearing stilettos in space [[BrokenHeel doesn't seem as smart now]], does it?), almost plummeting into the lava. Knuckles grabs her and hoists her back up.
* TakeThat: During development, the San Francisco-based devs were constantly being given parking tickets by attendants driving small three-wheeled cars. They retaliated by adding replicas of those cars into the game as G.U.N. vehicles and [[CatharsisFactor allowing them to be shot up and destroyed]].
* ThematicSequelLogoChange: The logo has a blue top spiral half to represent Sonic, and a black and red bottom spiral half to represent Shadow, who debuts in this game.
* ThemeNaming: The Eclipse Cannon and Project SHADOW--an eclipse is an astronomical event where a celestial body casts its shadow on another celestial body.
* ThemeTuneRap: Most of Knuckles' stage tracks take the form of raps about where he is, what's in the level, his goals and motivations, and bits of the game's story where applicable.
* ThirdLineSomeWaiting: Knuckles's and Rouge's race for the Master Emerald shards is an ExcusePlot to keep an otherwise uninterested Knuckles involved in the game--he wants to get to Rouge and the emerald shards she's collected. Knuckles only contributes to the heroes' efforts when they invade Eggman's pyramid base[[note]]For Knuckles, that's one level out of five[[/note]] and when the complete Master Emerald is used during the Last Story--and the latter event is for all practical purposes [[DiabolusExMachina immediately negated]] by the TrueFinalBoss. He doesn't even interact with the heroes until after his first three levels have been completed.
* ThisCannotBe:
** In the G.U.N. boss fights, a G.U.N. soldier will utter this when defeated.
** Also, the Dark characters will utter this when they are defeated for the final time.
-->'''Rouge:''' This can't be true! I never lose!\\
'''Eggman:''' No! I can't lose to ''Tails''!\\
'''Shadow:''' Impossible! I am the ultimate life form!
* ThisIsUnforgivable:
** Tails vows to never forgive Eggman for [[spoiler:blowing Sonic to smithereens, (or so he and Amy think)]].
** Also, Shadow's [[spoiler:initial]] thoughts about Maria's death.
* ThisLooksLikeAJobForAquaman: A more literal sense than most applies to the watery Chaos Zero from the ''Sonic Adventure 2 Battle'' multiplayer, who can notably breathe underwater indefinitely, an ability that may give him great advantages on the handful of Treasure Hunt stages that have water, but is otherwise useless.
* ThrownOutTheAirlock: Eggman traps Sonic and ejects him from the space colony in an EscapePod wired to explode.
* TimeLimitBoss: Sonic's and Shadow's {{Boss Battle}}s with GUN's {{Chicken Walker}}s both feature piles of stacked crates that they can use to attack the boss while it's still in its flying pattern. Wait too long, however, [[DownplayedTrope and the mechs will destroy the crates with machine-gun fire]], restricting the window of opportunity for the player to attack to only when the mech lands, dragging the fight out that much longer.
* TimedMission:
** The Treasure Hunt stages award points for how quickly each of the stage's three treasures is found; the player can use hints to isolate the location faster, but each hint shortens the amount of time the player is given to find that treasure. Despite the pressure, it's possible to get all three hints and still earn enough points for an A Rank.
** The penultimate section of Metal Harbor requires Sonic to board a rocket within 15 seconds before it lifts off.
** In the story, [[JustifiedTrope Team Dark is using time-bombs to blow up Prison Island]], which turns multiple stages into examples. Security Hall gives you five minutes to complete it, while Green Forest and White Jungle give you eight and ten minutes, respectively.
** Every stage's fourth mission requires beating the level within a given time frame, with the specific time varying by level. Fourth missions for levels that already have timers just give you less time.
** During the final Sonic/Shadow boss fight, if you don't beat the boss within ten minutes, the platforms will end and you will fall to your death.
** The TrueFinalBoss has to be beaten within five minutes. [[spoiler:If you don't, the Finalhazard breaches Earth's atmosphere and kills everyone.]]
* TitleDrop: This exchange from Shadow and Sonic.
->'''Shadow:''' What are you, anyway?\\
'''Sonic:''' What you see is what you get! Just a guy that loves '''adventure!''' I'm '''Sonic the Hedgehog!'''\\
'''Shadow:''' I see. But you know, I can't let you live. Your '''adventuring''' days are coming to an end!
* TonightSomeoneDies: The trailer for the Hero story ends by saying "Farewell, Sonic... forever." This refers to [[spoiler:Sonic's apparent death by space capsule]]... but teasing such doesn't make much sense, since you only get to see this trailer if you've already beaten the Dark story and thus already know that [[spoiler:Sonic survives]]!
* TooGoodForThisSinfulEarth: Maria was Shadow's best friend and her death is what leads to him vowing to take revenge on the entire world. [[spoiler: He assumed Maria's last wish for him to do so but, after fully remembering, it was actually to make sure the people on earth could have a chance to be happy.]]
* TooLongDidntDub: Many minor vocalizations and grunts in the dub were left untranslated, but not undubbed--the English voice actors simply reread the original Japanese. These include Eggman's "Yosh" when petting a chao, and his grunts when pulling and pushing items[[note]]If you listen closely, it becomes clear that they're Engrish sayings of "push" and "pull"[[/note]], as well as Sonic's "Teriaaaaaa!" when fighting Egg Golem in the Dark Story cutscene.
* TookALevelInBadass:
** Eggman, rather than relying on an army of MechaMooks in this game, mostly does his own dirty work, apart from aid from Shadow and Rouge, and he blows away entire armies in a machine that's nowhere nearly as intimidating as the huge machines he had in the last game, and he's FAR more competent than in any other appearance in the series.
** Zigzagged with Amy. In the story mode, she's reduced to an NPC and is left out of the action. In the multiplayer mode, however, she's a MovesetClone of Sonic, which means that she's much more maneuverable than in the first ''Adventure'' game (though she still lags behind the other hedgehogs).
* TotallyRadical: Some of the stunt bonus titles ("Jammin'!", "Tight!", etc.) have this feel to them, although it fits with Sonic's MascotWithAttitude style so it isn't out of place.
* TragicKeepsake: [[spoiler:Although it only happens for one game, Sonic gives Rouge Shadow's inhibitor ring after he supposedly dies.]]
* TranslationNod: During Dr Eggman's DoNotAdjustYourSet broadcast, text behind him displays both Eggman and Robotnik, the latter of which is his former English DubNameChange. In the same game, Robotnik is the surname of Eggman's grandfather and cousin in both Japanese and English.
* TrueFinalBoss: [[spoiler:Biolizard. It then went on to fuse with the Space Colony ARK, becoming Finalhazard.]]
* TubeTravel: In the Crazy Gadget stage.
* TwoGirlsToATeam: Rouge and Amy both play a significant role in the game's story. Tikal is also playable, but her role is reduced from Adventure 1 as she's only relevant in battle mode.
* TwoGuysAndAGirl: The "Dark" story mode. Shadow and Eggman are the guys, while Rouge is the girl.
* TwoLinesNoWaiting: ([[ThirdLineSomeWaiting The Master Emerald subplot]] notwithstanding) The Hero Story is a straightforward tale of Eggman's plot to TakeOverTheWorld with his new cohorts Shadow and Rouge, while the Dark Story is a dive into Shadow's and Rouge's {{Hidden Agenda|Villain}}s. The Last Story ties both lines together.
* TheUglyGuysHotDaughter: Maria Robotnik, the granddaughter of [[MadScientist Gerald Robotnik]].
* UltimateLifeForm: Shadow has the honor of [[TropeNamer naming the trope.]] He's the ultimate life form, created by Gerald Robotnik for GUN, believing it would help cure his granddaughter's terminal illness. Since Shadow is just as capable as Sonic, this puts Shadow at odds with the Blue Blur, as Shadow is consistently surprised that Sonic can match him -- or even surpass him.
* UncommonTime:
** The intro music starts out in 12/4 as Sonic and Shadow are being introduced, then it changes to 11/4 as Tails and Eggman are being introduced, then 10/4 as Knuckles and Rouge are being introduced. It then switches to CommonTime for the rest of the intro.
** Mad Space's BGM is in 7/8 time.
** There's one part of Sky Rail's BGM that is in 9+10+9+7+7/4.
* UndergroundLevel: Aquatic Mine. Doubles as UnderTheSea and potentially DownTheDrain.
* TheUnfought: This game marks the first time that Sonic doesn't ''directly'' fight Eggman. This is justified since this game is mainly focused on heroes fighting their gameplay counterparts (Tails vs Eggman, Knuckles vs Rouge, and Sonic vs Shadow).
* UngratefulBastard: Rouge's response to Knuckles saving her life was angrily snatching her hand away from him, thus leading the two resuming their arguing. Then it's subverted when she gives him back the pieces of the Master Emerald that she stole, under the premise "they stink like echidnas do". Of course, when Knuckles thanks Rouge and apologizes to her, [[WhenSheSmiles she actually smiles]] [[{{Tsundere}} back at him]] after he leaves.
* UniqueEnemy: There's a red version of the [[http://info.sonicretro.org/Hornet-3 Hornet-3]] (the flying robot that's armed with 3 bombs that they launch towards the player when they get near) called the [[http://info.sonicretro.org/Phoenix_(robot) Phoenix]], which [[RedOnesGoFaster goes faster]] than the stock model. They only appear in the Hard Mode version of Meteor Herd; none appear in Meteor Herd's normal mode, or in any other level, normal or hard mode.
* UnlockableDifficultyLevels: Every stage of the story has a hard version. Unlocking them requires clearing the first four missions of the stage, with hard mode serving as the fifth and final mission.
* UpdatedRerelease: ''Sonic Adventure 2: Battle'' for the [=GameCube=] features an overhaul on the game's multiplayer features, added new stages, readjusted the playing system so playing three games are no longer required, implemented an options for the [=2P=] Battle mode games, all characters that were previously unlockable by getting "A" ranks with certain characters from the Dreamcast version are available from the start, and the [=2P=] Battle mode runs at 60 FPS instead of 30 FPS. The extra characters themselves were also tweaked so they are no longer simply clones of the existing Team Sonic/Dark characters, however, Big the Cat in this version was replaced by the Dark Chao Walker. The game also features some gameplay tweaks, touching up some main character's models and shading, some gameplay refinements, and expanded on the Chao Garden. This version, however, did come with some downgrades with the visuals (especially during story cutscenes), a few missing or broken effects, and some sound mixing issues. ''Sonic Adventure 2: Battle'' would later serve as the basis for the HD port of ''Sonic Adventure 2'' on Xbox 360, [=PlayStation=] 3, and PC, with the extra multiplayer features from ''Battle'' being sold as DLC, however, some of the issues from the [=GameCube=] port are worse in the HD version (e.g. the sound mixing, missing features that required connectivity with the Tiny Chao Garden).
* UnintentionallyUnwinnable: Downplayed. You can automatically earn an "A" rank in a level by collecting every ring. This is impossible on certain levels because some rings are placed in areas that you can't reach without going outside the game's limitations. White Jungle is super-guilty as an entire prototype level layout (for Green Forest, weirdly) is stored within the level data, resulting in almost half of the rings being unobtainable (you max out at 287 rings out of a "possible" 462).
* UpgradeVsPrototypeFight: This happens [[spoiler:in the Final Story where the two ultimate life forms fight. Shadow, the perfected one, vs. the Biolizard, the failed prototype.]]
* VideoGameCaringPotential: 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.
* VideoGameCrueltyPotential:
** Chao. You can hit it, 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. With the introduction of Light and Dark Chao in this game, ''who'' is treating the Chao good or bad matters as much as ''how'' they're treated. So treating your Chao nicely with Shadow, Eggman, and Rouge will make them Dark as well as being cruel with the good guys will, and vice versa.
** Omochao is another source of cruelty potential as mentioned above, but even Chao ''lovers'' like to torture the thing (the fact you can even interact with it at all is probably the developers acknowledging that some players would likely tire of him [[AnnoyingVideoGameHelper offering bits of advice even after no one was interested]]). [[WhatMeasureIsANonHuman Then again, it is a robot that just looks like a Chao and is not an actual Chao]]...
** In one subversion, you can choose to put down Omochao instead of throwing him around like many players would do, and he'll thank you in one of the dialogues.
* VillainBall: Dr. Eggman, having detected the signal of one of the GreenRocks near his base, accidentally finds he's detected the Master Emerald and not one of the Chaos Emeralds. He has no current use or plans for it, but snatches it anyway, and throws in a dig at Knuckles, both of which only prompt Knuckles to shatter it.
* VillainProtagonist: The Dark Story has you playing as Shadow, Rouge, and Dr. Eggman, marking the first time in the ''Sonic'' series where you could play as the bad guys.
** Averted, as Shadow isn't really evil; just a hedgehog with misplaced vengenace over the death of his friend and possibly "programmed" to carry out this retribution by his late creator. Rouge is at most, an AntiHero who works as a spy for the government, rather than being a particular malicious character, like Eggman.
* VillainousLegacy: Gerald Robotnik. The main conflict of the story is against Eggman, but it was Gerald's actions 50 years in the past that caused many of the problems in the game... and in a few of the sequels.
* VirtualPet: The Chao, which can be reared by each of the six playable characters from the main campaign and trained using small animals and Chaos Drives collected from the main character stages. New to this game is a system of EvolutionaryLevels allowing the Chao to evolve into either Hero or Dark Chao depending on how they're treated by the various characters. The system would go through a complete overhaul for the [=GameCube=] versions.
* WhamLine:
** The Hero Story has this right before Green Forest, since the heroes (and by extension, the player if they haven't done any of the Dark Story first) have absolutely no idea what Eggman is planning:
--->'''1st Mission:''' [[TimedMission Escape from the island in 8 minutes!]]\\
'''Dr. Eggman:''' (''over Shadow's device'') Shadow! What are you doing? Hurry and get back here right now before [[TimeBomb the island blows up]] [[OhCrap with you on it]]!
** Also from the Hero Story; after Eternal Engine, Sonic is just about to put the fake Chaos Emerald into the Eclipse Cannon...''and then you hear Eggman on the walkie talkie.''
--->'''Dr. Eggman:''' Tails, tell Sonic to meet you back at the research facility! Now!\\
'''Tails:''' Sonic, [[HostageSituation Amy is--]]
** This line from Dark Story reveals that somebody from Team Dark is not what they seem:
--->[[spoiler:'''Rouge''']]: [[spoiler:''(into communicator)'' [[TheMole This is Rouge reporting]]!]]
** In Last Story, it's clear something's wrong from the moment [[spoiler:the Eclipse Cannon refuses to fire]], but it's not clear what until this bombshell gets dropped:
--->'''Rouge:''' [[spoiler:It's all over for us]].\\
'''Knuckles:''' What do you mean?\\
'''Rouge:''' I've just received a message from my boss. [[spoiler:The space colony ARK is currently [[ColonyDrop approaching the Earth at an incredible velocity. It probably... will impact Earth]]]].
* WhenSheSmiles: Rouge is depicted of making seductive and devious expressions, but after Knuckles leaves after restoring the Master Emerald, she gives out a tender smile at him, marking a sign of her true feelings for Knuckles.
* WhiteAndGreyMorality: The marketing of this games' story gives off the impression of a "good team vs. evil team" plot, but it is actually more of a case of good vs not-so good. The hero team of Sonic, Tails, and Knuckles are undeniably good. Rouge is a sneaky AntiHero jewel thief, but [[spoiler:is also a hired undercover spy for the President who is sent to uncover Eggman's plot and is actually GoodAllAlong]], and Shadow is a morally conflicted amnesiac character who is out for revenge over the death of his closest friend Maria (That is, until he finally remembers what he promised and what she really wanted). The most villainous character is Eggman, and even then he ends up being [[EvenEvilHasStandards not all that bad]] [[AntiVillain either]].
* WoobieDestroyerOfWorlds:
** Gerald becomes somewhat sympathetic once you realize how he lost ''everything'' important to him. To see how far Gerald fell, just watch the cutscene in ''VideoGame/ShadowTheHedgehog'' where he instructs Shadow (via old video footage) to use the Eclipse Cannon ''for the good of humanity by destroying the Black Comet''. All it took was the death of Maria for Gerald to go insane and completely alter his motives.
** Shadow the Hedgehog also counts for this to a certain degree. The reason he's attempting to destroy humanity? Because he thought that his promise to Maria was for ''revenge''. And as it turns out, that was actually a fake memory created by Gerald so he could carry out his revenge on humanity.
* WorthyOpponent:
** Eggman displays a sudden spike in competence when he locks Sonic in a space pod and then fires it into space--and then blows it up for good measure. As he overlooks the explosion, Eggman solemnly declares Sonic an "admirable adversary."
** Shadow had a similar reaction: When witnessing Sonic's seeming death, Shadow says "Looks like he was simply an ordinary hedgehog after all" with a tinge of disappointment. Curiously both Eggman and Shadow are somewhat nonchalant, even amused when realizing he survived, Shadow even directly telling him he managed to impress him.
* WouldHitAGirl: Knuckles had no qualms in attacking Rouge, who can hold on her own against him. However, he reluctantly apologizes for this after restoring the Master Emerald. Besides, Rouge ''is'' a thief, so Knuckles has a right to do so.
-->'''Rouge:''' You call yourself a hunter, attacking a lady? Shame on you!\\
'''Knuckles:''' What kind of lady goes around stealing gems anyway?!
* YouJustToldMe: Eggman pulls a magnificent one on Tails and Sonic when they come to rescue Amy.
-->'''Eggman:''' You thought you could trick me with that fake emerald, didn't you?\\
'''Tails:''' So... how did you know it wasn't the real one?\\
'''Sonic:''' Tails!\\
'''Eggman:''' Because ''you just told me, fox boy!''
* YourPrincessIsInAnotherCastle: Shadow the Hedgehog is secretly planning to carry out {{Revenge}} for Maria by booting up the Eclipse Cannon and using it to blow up the planet, [[spoiler:but Gerald Robotnik has a backup plan in case the laser fails to cause a ColonyDrop and destroy the world that way.]]
* YourSizeMayVary: In ''VideoGame/SonicAdventure'', the Master Emerald was as big as a car. In this game, it's about as tall as Knuckles. Also present within the game itself. In the cutscene before Cannon's Core, it's much smaller than usual even in this game, being able to fit in Knuckles' hand.
* YoYoPlotPoint: After Sonic and company board the space shuttle and try to board the ARK, the shuttle [[DiabolusExMachina is struck by a meteor]] and the hatch rips open. The Master Emerald shards Knuckles had already collected come pouring out and prompt Knuckles and Rouge to go hunting for them--this is mostly an {{excuse|plot}} to give Knuckles and Rouge levels in space.
[[/folder]]
----
->''"C'mon! Let's go home -- to the planet as cool and blue as me!"''
----

* EarlyBirdCameo: Chaclon ([[SpellMyNameWithAnS Chacron? Chaclone?]]), the BrilliantButLazy rival from the Chao Race of ''VideoGame/SonicAdventure'' returns... but because ''Sonic Adventure 2'' was adapted to the [=GameCube=] before the first ''Adventure'', series-fresh players were liable to encounter him in Challenge Races with ominous titles like "He Returns" and "He Strikes Back"--[[RememberTheNewGuy without any idea of who "he" was]].

* TooGoodForThisSinfulEarth: [[spoiler:Maria's last wish for Shadow was to make sure the people on earth could have a chance to be happy.]]

->''A new day brings new adventure. But for now... [[ThatsAllFolks rest easy, heroes.]]''

->''[[ThatsAllFolks A new day brings new adventure. But for now... rest easy, heroes.]]''

->''"C'mon! Let's go home -- to the planet as cool and blue as me!"''

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/1e889aed_e2fd_4449_babd_c479f439d603.png]]

** The ARK was shut down because the GUN higher-ups did not trust Gerald or his research. [[spoiler:When they heard about the violent tendencies of the Biolizard, they used it as a justification and cover-up for their killing of the personnel, placed the blame on Gerald, and forced him to continue working under their scrutiny before executing him.]] This is explained in full in [[https://info.sonicretro.org/Sonic_Adventure_2_-_The_Truth_of_50_Years_Ago... the Japanese version of the strategy guide.]]

* BilingualBonus: An army called G.U.N. is not just a [[IncrediblyLamePun horrible pun in English]]; "gun" is also the Japanese word for "army".

''Sonic Adventure 2'' was the long-awaited sequel to ''VideoGame/SonicAdventure''. It is historic for three reasons: it's one of the [[UsefulNotes/SegaDreamcast Dreamcast]]'s final releases, being released three months after the Dreamcast's official discontinuation, it came out on the franchise's [[MilestoneCelebration 10th anniversary]], and it wound up being the last ''Franchise/{{Sonic|TheHedgehog}}'' game made before Creator/{{Sega}} quit making consoles and went third-party.

The Chao races from ''[=SA1=]'' are expanded upon, with players able to raise "Hero" or "Dark" Chao depending on which character interacts with them. The game was {{updated|rerelease}} for the UsefulNotes/NintendoGameCube several months after the Dreamcast version as ''Sonic Adventure 2: Battle'', which added yet-more Chao stuff and completely overhauled the 2-player mode, which is probably where the "Battle" subtitle comes in. The [=GameCube=] port was the first ''Sonic'' game ever released on a Nintendo home console.

Following the success of its predecessor, an [[UpdatedRerelease HD version]] of this game was released for UsefulNotes/XBox360 and UsefulNotes/PlayStation3 (through UsefulNotes/XboxLiveArcade and UsefulNotes/PlayStationNetwork respectively) on October 2nd, 2012 for $10; the additional two-player modes of ''Sonic Adventure 2: Battle'' are DownloadableContent for $3. The game was also released on PC via UsefulNotes/{{Steam}} on November 19th, 2012, marking its official PC debut.

** Amy was a playable character with her own story route that gave her some much needed CharacterDevelopment in ''VideoGame/SonicAdventure''. In this game, she's more of a supporting character and is only playable in the multiplayer races and doesn't really accomplish a lot aside from sneaking around in Prison Island and freeing Sonic from prison and being indirectly responsible for saving Earth by convincing Shadow the Earth and its people aren’t all horrible, which triggers memories of Maria’s last wish to Shadow. As a result, Shadow performs a HeelFaceTurn and helps Sonic and the others with the Biolizard.

** Amy was a playable character with her own story route that gave her some much needed CharacterDevelopment in ''VideoGame/SonicAdventure''. In this game, she's more of a supporting character and is only playable in the multiplayer races and doesn't really accomplish a lot until the Last Story.

** Why did GUN arrest Sonic? Were they using him for a patsy to hide Shadow's existence? [[AllegedLookalikes Was it an honest mistake?]]

* ColorCodedForYourConvienence: Chaos Drives are different color depending on the stat they're associated with in the Chao Garden. The animals you can find in each stage also have colored backgrounds for the same thing: