* SugarWiki/AwesomeMusic: What do you expect from something in the [[AwesomeMusic/SonicTheHedgehog Sonic series]]?
** For themes with lyrics we have all of the ending themes, but especially [[https://www.youtube.com/watch?v=D2Qa2J4j3_8&channel=Elmo185 All Hail Shadow]], and [[https://www.youtube.com/watch?v=_kTBbTSjZpI&channel=blackblur7 I Am All of Me]] for the main theme. Most of the background music also counts.
** And for the final Ending music, we have [[https://www.youtube.com/watch?v=oVIO1t9tYuE Never Turn Back]].
** Listen closely to the song that plays when Shadow transforms into his Super form - Towards the end, the guitar riff from [[https://www.youtube.com/watch?v=rM85TNMnUkA Live & Learn]] can be heard.
** Not necessarily from the game, but m-flo's [[http://www.youtube.com/watch?v=9BRAWLNaA1g remake of Tripod Baby]] for the game is rather interesting.
** It can be argued that music describes what goes on in a character's head in ways that dialogue can't. [[https://www.youtube.com/watch?v=Jl26fda_1PE&channel=blackblur7 The Chosen One]] does a great job at proving this point by explaining how [[WoobieDestroyerOfWorlds Shadow regrets the doom that he brought to the world]], but in the end, he is [[TheChosenOne the last hope for humanity]].
** The [[https://www.youtube.com/watch?v=2wLYtj_yq8E&channel=BrawlBRSTMs3 "Eggman" Remix]]. Eggman is listening to it in-game - tapping his foot to it - and there's a full version of it on the soundtrack.
* [[Awesome/VideoGameLevels Awesome: Video Game Levels]]:
** Digital Circuit. Not only is the {{Cyberspace}} concept a very unique one among Sonic levels, but the sections where you race along internet circuits are really fun, and the platforming is quite well-done in the level. Technically there are puzzles, but they require something less than the brainpower of a slug to solve. Mad Matrix is another Cyberspace level in the same vein, and is just as good (unless you don't like the mission where you must destroy several bombs).
** Lethal Highway. Of all the levels in the game, it's the closest in terms of design to the well-received ''VideoGame/SonicAdventure2'', meaning that you can just skate along the highway at full speed, and near the end, it homages [[VideoGame/SonicAdventure Speed Highway]]. It also has motorbikes.
** The Dark mission in Air Fleet - chasing and shooting down the president's escape pod - is a wonderful mix of fast-paced Sonic gameplay combined with third-person shooting. It's one of three missions with that mechanic, one of the other two being Lethal Highway above.
** Circus Park is a bright colourful amusement park with lots of great level gimmicks, Eggman being really exciteable about it due to him creating it, and good uses of the gunplay, such as in shooting gallery sections.
** GUN Fortress. Unusually melancholy music, wide open spaces, lots of space to run around, a sense of progression that many levels in this game don't have, and a Dark mission where you can cause massive carnage.
** Sky Troops, which has a great sense of speed and platforming, set high up in the sky with great music and pretty good missions. It was popular enough to be included in fan mods of ''VideoGame/SonicGenerations''.
* BaseBreakingCharacter: To elaborate, the base was already pretty broken over if Shadow's return in Heroes was a good thing or not. This game did nothing but add fuel to that fire. In fact, this game cemented Shadow as ''the'' most divisive character in the series bar none. To this day, fans are split on whether he is still a good character who's just been the victim of overexposure and bad writing, or a glorified Marty Stu who should have died after his debut and does not fit with the whimsical nature of the series.
* BigLippedAlligatorMoment: In the ending, Eggman demands for the Chaos Emeralds while sneaking away with Knuckles chasing after him as Sonic and the others start laughing.
** Because of how many combinations of level sequences there are (326!), this happens sooner or later.
* BreatherBoss: The Egg Breaker in Iron Jungle (and Iron Jungle only, Mad Matrix and Cryptic Castle have harder fights) is ridiculously easy if you go behind the start and spam the turret. You can beat Eggman in 7 seconds this way.
** The boss fight against Heavy Dog at The Doom. It's fairly annoying, but not difficult, especially considering how horrendous The Doom can get in all three of its missions.
** The Egg Dealer, which appears as the final boss of four of the ten endings, is also not particularly difficult or annoying compared to Black Doom or Sonic and Diablon, who both fall right into GoddamnedBoss territory.
* BreatherLevel: Any level where you just have to get to the end, especially if you were doing Hero or Dark missions before. Getting to the end is easier than finding stuff. However, The Ark's Normal mission stands out - all you do is just fly on a Black Arms bat thing for the entire level, only you were required to do the Dark missions of either Central City or The Doom to get here, both of which are ThatOneLevel and detailed on this page.
* CatharsisFactor: When you max out either your hero or dark meters, you're given complete invincibility and infinite ammo for whatever gun you're carrying until the meter runs out. You can see where this is going...
* CompleteMonster: [[NamesToRunAwayFrom Black]] {{Doom|yDoomsOfDoom}} is [[BigBad the leader of the Black Arms]] and a [[KnightOfCerebus completely humorless]] EvilutionaryBiologist. First he helps Gerald Robotnik make an immortal creature out of his own DNA in return for the Chaos Emeralds. This is a trick, since he plans to gather the Chaos Emeralds to become [[AGodAmI godlike in power]], then just use humans ToServeMan, [[ImAHumanitarian ''if'' you know what I mean.]] He throws his own soldiers at the heroes of Mobius like tennis balls, and has no issues with [[YouHaveOutlivedYourUsefulness destroying his own son]] once the job is done, no matter whose side Shadow takes. He forces Shadow to relive Maria's death to manipulate him, and destroys an entire city with the Eclipse Cannon. He paralyzes Sonic and co, and billions more on the planet, to allow his offspring to eat them alive. [[{{Hypocrite}} Hypocritical]], ruthless and uncaring to even his own, Black Doom is [[VileVillainSaccharineShow among the worst]] the world of ''Sonic the Hedgehog'' has to offer, even today.
* CreatorsPet: What half the ''Sonic'' fandom sees Shadow as. Considering it has actually been confirmed that Shadow (and Sonic) are Takashi Iizuka's favorite characters, and Iizuka being Shadow's creator, it not hard to see why.
* HeReallyCanAct: Well, He Really Can Change His Voice more like; say what you will about the game in general, but an unambiguous positive is that ''Jason Griffith'' [[https://youtu.be/Z6sH1M8C2CE?t=14s improved immensely on]] his Shadow voice compared to [[https://youtu.be/1wt2EPG9GNU?t=2m12s this]].
* HilariousInHindsight:
** The game has quite a bit of swearing. Swearing done by ''[[Creator/FourKidsEntertainment 4Kids]]''.
** Sonic says he "wouldn't be caught dead" using a gun. As we all know, in ''[[VideoGame/SuperSmashBros Brawl and U/3DS]]'', while [[FamilyFriendlyFirearms they're lasers and such]], he can still [[HypocriticalHumor utilize a gun]]. ''VideoGame/MarioAndSonicAtTheOlympicGames'' also has its share of shooting events.
** [[spoiler:Shadow has alien DNA]]. The only reason this is spoiled is because it's almost identical to a plot twist from [[Anime/KillLAKill another story starring a black and red edgy character]].
* HoYay.
** One of the pathways to get to the pure hero ending is "Under The Name Of Love". In that pathway, it goes like this: Neutral Westopolis, Hero Glyphic Canon, Neutral Circus Park, Neutral Mad Matrix, Hero Space Gadget and Hero Final Haunt. You help Knuckles in Glyphic Canon, but go back to being neutral for a while, and it isn't until Sonic comes into the picture to give the final push to being pure hero. It's almost like [[LoveRedeems Sonic's love redeemed Shadow]]. Ok, Knux helped a little, but still, you could go either way. With Sonic, it could also dip into FoeYay territory.
* LoveItOrHateIt: While the game's tone and presentation is nigh-universally despised, the gameplay itself is polarising. The controls are functional and level design promotes a mix of speed, platforming, and exploration as expected from the series. Gunplay is also fully functional, consitering Sonic Team doesn't do guns much. Others consider it as big a problem as the tone, with slippery controls retained from ''Heroes'', repetitive level design, tedious missions, and poor design issues such as being forced to kill enemies of the opposite alignment on certain routes.
** Perhaps the most notable thing about the game is that despite it not being part of the main series, it is unforgotten even to this day. Every Sonic fan knows of it, even if they haven't played it. One of the main plot complaints is how many loose ends it has left.
* MemeticMutation:
** "Where's that ''[[AvoidTheDreadedGRating damn]]'' fourth Chaos Emerald?"
*** Fun fact: In ''VideoGame/SonicGenerations'', [[FandomNod Shadow guards that damn fourth Chaos Emerald.]]
** "Find the Computer Room!", which both the fanbase and SEGA launched on top of to create the sneakiest injoke of Summer of Sonic '09 - in particular, putting up confusing signs to the computer room. Of course, it's also in the placeholder for [[http://www.sonic-city.com Sonic City]], and even became the name of a website.
** [[MostAnnoyingSound "You know what they say: The more, the merrier!"]]
** "Mr. Yuji Naka is alright!"
** [[http://i0.kym-cdn.com/photos/images/original/000/652/918/68a.jpg Ow, the Edge.]]
** "THIS IS WHO I AM!"
** "MARIIIAAAAA!"
** "Looks like these black creatures really mean business!" and various other lines in game to that effect are popular to bring up, making fun of the fact that ''everyone'' constantly mentions what color the aliens are in a way that makes them sound like psychotic racists.
** "This is like taking candy from a baby, [[PokeThePoodle which is fine by me]]."
* MoralEventHorizon:
** Shadow puts his current total of five Chaos Emeralds into the Eclipse Cannon and uses it to completely destroy a capital city. But then, this trope is averted thanks to NoEndorHolocaust.
** On a different path, Shadow deliberately tries to kill the fleeing president, who is previously shown to be almost comically upstanding (''and'' to have a great deal of respect for both Shadow and Sonic). Shadow fails to accomplish this as well.
** His final chance to cross it for certain paths can count as a success. In three of the endings, [[spoiler:he decides to kill everyone's favorite eggheaded scientist.]]
** Black Doom's xenoforming of the planet and [[HumanResources consumption of its inhabitants]] was bad enough, but then he had the balls to claim that he's trying to ''save'' humanity. He's either got a serious case of BlueAndOrangeMorality or (more likely) is trying to justify his actions.
* {{Narm}}: Even fans of the game concede that the game simply craps narm, start to finish. Every melodramatic cutscene fully qualifies, as does the voice-acting and the plot in general.
** Another particular moment is in the [[http://fat.gfycat.com/OldUnfitGalapagosalbatross.gif in-game intro]], where Shadow does a DramaticGunCock with an SMG... by [[GunsDoNotWorkThatWay pumping it like a shotgun.]]
** When you make a selection on the selection screen, the sound effect is a handgun firing.
** Many of the [[http://info.sonicretro.org/List_of_Library_sequences library sequences]] have incredibly melodramatic titles.
* NarmCharm: Of course, if you're a fan of the game you probably get off on this kind of game, and even people who don't like it have admitted that its hilariously toothless attempt at a DarkerAndEdgier Sonic game makes it memorable even today.
* OlderThanTheyThink: ''This'' was the game to introduce skydiving mechanics, not ''VideoGame/SonicUnleashed''. This is also the first game to involve parkour-esque wall-running mechanics as an expansion on the Triangle Jump, not ''VideoGame/SonicLostWorld''. It also features a [[VideoGame/SonicUnleashed boost]] although in a different form, and you can only use it if you go the hero path.
* PortingDisaster: This game was built from the same engine as ''Heroes'', and thus the [=PS2=] release of this game suffers from all of the same problems the [=PS2=] version of ''Heroes'' did.
** The Xbox version cuts Maria as a playable character.
* ScrappyMechanic:
** The weapons actually work better than you probably expect, but the ''vehicles'' are not so polished -- especially the motorcycle that shows up in the intro movie. The walkers work pretty well, though.
** The effectiveness of the weapons depends on what version you're playing. Works pretty well on the Gamecube version but is utterly useless on the [=PS2=] version. Also, the targeting system seems to have issues when it comes to short-ranged weapons, yet works really well once you start getting medium to long-ranged weapons.
** Additionally, no matter which path you take in a level, all the enemies will attack you, which forces you to kill them and have your assist character [[WhatTheHellHero chew you out for it.]] Notable in Cryptic Castle, where Eggman is the Dark assist character, but whether you choose to go with him or Amy, both of them will chew you out when you destroy Eggman's robots. This is especially bad when you ''need'' to defeat enemies to proceed, even if doing so will raise the gauge opposite of the mission you're going for, lowering your score.
** The "hunting" missions of every kind are terribly designed, which really hurt as they comprise about 60% of the whole game. You have no radar, and there are rarely "extra" enemies/stuff to find if you miss a few, and the only way to backtrack is to keep moving forward until you find another checkpoint. And all of these problems wouldn't be too bad, but the linear stage design just makes them unbearable, and it doesn't help that the monotone colors makes it really hard to find things. Team Chaotix had something like this in ''SonicHeroes'' (itself not well-liked either), only there you were only required to find half the things most of the time, rather than all of them, and there were more colours in that game so things stood out more.
* SoBadItsGood: Amongst the badly BrokenBase, some fans think the barely PG-13 violence and language, ridiculous plot and dialogue, and averaging gameplay make the game a {{camp}} masterpiece.
* ThatOneLevel:
** Cosmic Fall is a MAJOR pain in the ass because of the numerous tricky jumps over rotating platforms, and you'll have to fight with the awkward camera throughout the entire level; good luck beating this level on hard mode! The main saving graces are that both of its missions are to get to the end of the level (one is just further away), and parts of the mission are very fast.
** The Doom is easy to get lost in even with the use of the maps, which are as confusing as they are helpful, and the carrying of the Heal Units slows Shadow right down. Its (slightly) saving graces are that if you see a Heal Unit, you know a scientist is close-by, and how easy it is to use Chaos Blast over and over again thanks to the amount of destructible scenery.
** Even with The Doom slowing things down whichever way you play it, Lost Impact is the hardest, most tedious level in the game. It's slower due to the slow-moving GUN Lifts, with more Artificial Chaos to hunt - not to mention they are a powerful enemy. And on top of everything else, they are just about the only enemy that gives Hero points, so you won't even charge Chaos Control to speed your way in the Neutral mission.
** Central City. Take the bland visuals of Westopolis, add the maze like elements of The Doom and Lost Impact with the same issue of repetitive confusing visuals, no goal ring (so no Neutral mission to speed through), and an 8 minute time limit.
** Black Comet. Visually bland, repetitive level design, ridiculous length, and lots of liquid that acts as bottomless pits. It gets worse though - several sections require you to use the air saucers to maneuver across masses of liquid, only aliens AND military soldiers alike are shooting the hell out of you, and if the saucer runs out of health, down you go.
* TheyWastedAPerfectlyGoodPlot: The ''entire premise'' of Shadow deciding whether to be a hero or villain was simplified down to: "Maybe this guy knows about my past... no maybe this other guy." There's no involvement of actual character morals whatsoever, and the RandomEventsPlot nature of whatever route you take blocks out any CharacterDevelopment we might see from Shadow. Also, the Good/Neutral/Evil routes barely have an impact on the story, despite potential for compelling storytelling drama over whoever sees Shadow as an enemy or an ally. There isn't even an ending where Shadow sides with Eggman!
** In particular, Shadow's implied RoboticReveal towards the end of ''Heroes'' would have made things even more interesting... But it's only even really mentioned in the last two of the neutral-route levels, and thus the two endings where Shadow accepts this as fact are two of the absolute least canon, even when taking the game's story before the OmegaEnding as BroadStrokes. Instead, we just have to accept that Shadow had an UnexplainedRecovery after ''Adventure 2''. At least they do cover that [[spoiler:Shadow was rescued by Eggman as he fell, so at least it isn't left hanging, but only if you wait 9 minutes into the final boss, as it's never in any actual cutscenes]].
* TrueArtIsAngsty: Possibly the reason the game was created, and a common reason for it to be enjoyed.
* UglyCute: Some, or at least [[WebVideo/TheLostBoys ZeldaMaster]], find Black Bull cute in an odd way as stated in [[http://youtu.be/5lQzSxfz7TM this]] video.
* {{Wangst}}: This is the game that inadvertently set Shadow's characterization among the fanbase as this. Ironically, it's also the one where he actually gets over it.
* WereStillRelevantDammit: Some see the game's DarkerAndEdgier turn as Sonic Team doing this. While the game did sell relatively well, the backlash and eventual reception to ''Sonic '06'' along with issues concerning other aspects foiled their attempt to play this trope straight, leading to Yuji Naka backing out of Sega, Dimps being assigned onto the series alongside Sonic Team, and the BrokenBase problem becoming worse.
* WhatAnIdiot:
** The premise of the story is built on the fact that Shadow never asked any of his friends about his past, or never even told them that he was trying to search for clues to his past. Even if they never knew about the Black Arms' involvement, what they knew his past would have saved Shadow a lot of time.
** Eggman's Egg Dealer is a slot machine mech that, among other things, has the ability to [[TacticalSuicideBoss power up Shadow]]. This serves no function other than to hinder Eggman.