History FranchiseOriginalSin / SonicTheHedgehog

** ''Sonic Heroes'': Instead of six distinct characters or two distinct storylines, you have the same set of levels copy/pasted with minor difficulty and cutscene adjustments. This also results in all four teams somehow being able to destroy the same boss at around the same time (do they have to wait in line?). It feels like pointless busywork to unlock a final boss that easily could have been put at the end of a single, cohesive storyline covering all the necessary plot points.

** ''Sonic Heroes'': Instead of six distinct characters or two distinct storylines, you have the same set of levels copy/pasted with minor difficulty and cutscene adjustments. This also in all four teams somehow being able to destroy the same boss at around the same time (do they have to wait in line?). It feels like pointless busywork to unlock a final boss that easily could have been put at the end of a single, cohesive storyline covering all the necessary plot points.

* The [[HumanFocusedAdaptation show's focus on Wade and his family over Knuckles]] has become the target of massive criticism from fans. However, the films were also guilty of this, placing almost just as much focus on Tom and his family as it does on the Sonic characters (especially in the first film, where Tom was the co-protagonist). The difference is that the ''Sonic'' cast are still given a lot of focus in the films, with the second film putting a far greater focus on them, with the human characters (bar Robotnik for [[BigBad obvious reasons]]) becoming DemotedToExtra, while in the show, Knuckles becomes increasingly sidelined compared to Wade and the other human characters -- even becoming near absent in episode 4 -- which fans were not pleased with.

** After struggling to fix the problems that came with the series's VideoGame3DLeap for so long, ''Unleashed'' featured a mixture of 2D and 3D gameplay, with the 2D sections being fairly brief and integrating seamlessly with the 3D sections; this was well-received as it was the first time 2D Sonic gameplay had been featured on a console since ''Sonic 3&K''. ''Colors'' features an abundance of 2D gameplay, which some have criticized when looking back at the game. ''Generations'' splits the gameplay between 2D stages with Classic Sonic and 3D stages with Modern Sonic, but Modern Sonic's stages still feature a fair amount of 2D sections, which h tend to last longer than the sections in ''Unleashed''. ''Lost World'' features another 2D/3D mix, along with a lot of divisive new gameplay elements. By the time ''VideoGame/SonicForces'' was announced, many fans had begun to feel that the 2D sections had become a crutch to compensate for either not knowing how to implement quality 3D gameplay or for [[PanderingToTheBase pandering to Classic fans]], especially with ''VideoGame/SonicMania'' releasing in the same year. Classic Sonic's return, along with Modern Sonic once again having 2D sections in his levels, is one of the most common criticisms for ''Forces''.

* Sega's very loose policy on the canonicity of side materials (most notably the cartoons and comics) created a BrokenBase as early as ''1992'' -- one year after Sonic was introduced -- as Sonic fans started siding with one particular interpretation while viciously attacking the other ones, not unlike today's Broken Base with ''Sonic'' (only more so with gameplay than story, though the latter isn't rare either). During TheNineties, however, Sonic fans [[UsefulNotes/ConsoleWars had a common enemy in Nintendo and Mario]], so the cracks didn't become visible to most until 2001 with ''VideoGame/SonicAdventure2''. At that point, Sega exerted greater enforcement over canonicity, rendering all other storylines non-canon, followed shortly by its financial collapse and subsequent alliance with Nintendo. With the barriers torn down and no uniting force, the bickering became the ''Sonic'' fandom's most infamous trait.

** In the era from ''Adventure'' to ''Sonic '06'', a lot of focus was placed on the supporting characters. Many felt that this got out of hand, with the cast becoming too bloated, the different playstyles not being well executed, and not having enough Sonic in ''Sonic'' games. Starting with ''Unleashed'', Sonic Team drastically cast back the role of the supporting cast, with everyone except Tails making cameo appearances at best. By the time of Sonic's 25th anniversary, the other characters had been neglected for so long that many fans had become desperate to be able to play as them again, or at least wish for them to be given a more significant role in the plot. The final boss fight of ''Generations'' tends to receive a lot of scorn in particular, as the returning characters do nothing except cheer both Sonics on.
** Related to the above; the ''abundance'' of characters as well. Almost ''every'' game introduced a new major recurring character, starting with Tails (Sonic 2), Amy and Metal Sonic (Sonic CD), and Knuckles (Sonic 3). Initially, these characters were rather popular and considered fresh additions (and because of the GrandfatherClause, you'll find very few who hate these four in particular) that added to Sonic's world. But these characters became increasingly numerous, and started to overshadow Sonic himself, and were often tied to questionable gameplay styles. Public opinion started to turn against them, and fans demanded for the cast to be cut down, which led to the aforementioned era of having Sonic as the only playable character.[[note]]Barring sports spinoffs such as the ''Olympic Games'' series that crossed over with ''Franchise/SuperMarioBros'', which allowed for the other Sonic characters to be playable.[[/note]] However, for a time this basically resulted in poor Sonic himself basically being contorted to enable Sonic Team's inexplicable need and/or habit of shoving GameplayRoulette into their games (the worst example being the [[VideoGame/SonicUnleashed Werehog]], and Classic Sonic in ''VideoGame/SonicForces'' as well). The only games to actually avoid the trap of too many playable characters and/or the GameplayRoulette problem are ''VideoGame/SonicMania'' and, strangely enough, ''VideoGame/SonicAndTheBlackKnight'', of all games - the latter's surprisingly classic-style implementation is largely overshadowed by its main issues, but the example ''Mania'' that set is often cited as what Sonic Team should've been doing all along in this regard. One could argue that the focus on the number of characters in itself was fans and the developers missing the forest for the trees in that the problem was ''quality'', not quantity - a dozen playable characters who are ''optional'' that stick to a singular core gameplay structure but still have their own interesting traits and abilities is more likely to be more palatable and provide replay value rather than a dozen ''mandatory'' characters who have completely different gameplay (most of questionable quality)[[note]]or in the case of ''Heroes'' literally a dozen characters in four teams that play ''almost literally identically'' and playing all four campaigns is also mandatory to get the final story, which results in a [[{{Padding}} completely different problem]][[/note]], which is why the approach taken by ''Black Knight'', ''Mania'' and later ''VideoGame/SonicSuperstars'' is considered to be the best one. Tails, Knuckles and Amy being playable in the DLC of ''VideoGame/SonicFrontiers'', while still rough around the edges, is also regarded as a huge improvement over previous attempts at handling multiple playable characters in mainline 3D Sonic games.
** After struggling to fix the problems that came with the series's VideoGame3DLeap for so long, ''Unleashed'' featured a mixture of 2D and 3D gameplay, with the 2D sections being fairly brief and integrating seamlessly with the 3D sections; this was well-received as it was the first time 2D Sonic gameplay had been featured on a console since ''Sonic 3&K''. ''Colors'' features an abundance of 2D gameplay, a fact that some have criticized when looking back at the game. ''Generations'' splits the gameplay between 2D stages with Classic Sonic and 3D stages with Modern Sonic. Despite this, Modern Sonic's stages still feature a fair amount of 2D sections which tend to last longer than the sections in ''Unleashed''. ''Lost World'' features another 2D/3D mix, along with a lot of divisive new gameplay elements. By the time ''VideoGame/SonicForces'' was announced, many fans had begun to feel that the 2D sections had become a crutch to compensate for not knowing how to implement good 3D gameplay, and that Classic fans were being unfairly pandered to, especially with ''VideoGame/SonicMania'' releasing in the same year. Classic Sonic's return, along with Modern Sonic once again having 2D sections in his levels, is one of the most common criticisms for ''Forces''.
** Classic Sonic's original introduction in ''Generations'' is a move that was universally praised. Because of that game's massive success, Sega began to market Classic Sonic heavily in the following years, giving him multiple appearances in other games, his own comic book, his own anniversary title in ''VideoGame/SonicMania'', and his own web animation miniseries. While the fanbase loved his inclusion in ''Generations'' and products featuring him tend to sell well, many fans increasingly criticized Sega's seeming decision to treat him as his own separate character, instead of a younger version of Sonic. The decision to make him a HeroicMime also makes it difficult for him to distinguish himself from his modern counterpart. When the first trailer for ''VideoGame/SonicForces'' was released, the reaction to Classic Sonic's appearance was much more ambivalent than it was for ''Generations'', with many fans questioning why he needed to be there (which gave the game the derisive nickname of ''Sonic Generations 2'', not helped by the fact that Sonic Team promised that it wouldn't be a sequel to ''Sonic Generations'' gameplay wise). Whereas Classic Sonic was considered a great idea when he only appeared in ''Generations'', these days he tends to be held up as a symbol of Sega relying too much on nostalgia-pandering and making the franchise seem stuck in the past, instead of being willing to truly push the gameplay forward.
** Starting from ''VideoGame/SonicAdventure'', the games would go on to have [[CerebusSyndrome increasingly dramatic and over-the-top storylines]]. Initially, this was pretty well received, or at least wasn't considered a problem. However, by the time ''VideoGame/ShadowTheHedgehog'' rolled around, consensus was that the series became ''too'' melodramatic for its own good, and the questionable executions of said melodrama led the reputation of the series to tank, reaching its nadir with ''VideoGame/SonicTheHedgehog2006''. Sega seemed to have got the message and subsequent games became much DenserAndWackier as a result, which ironically created ''another'' sin in the form of people starting to feel the series veered too far in the ''other'' direction and became ''too'' juvenile and lighthearted with games like ''VideoGame/SonicColors'' and ''VideoGame/SonicLostWorld''.
** Even the [[VideoGame/SonicTheHedgehog1 original game]] foreshadows Sega's many questionable design choices to come. The game was sold on its speed, yet at least half of its stages require slower, more methodical platforming, which not only goes against players' instincts, but the momentum physics actually work against the player in such levels. What makes it less discussed for this is mostly that Green Hill Zone, the first stage, works very well as an opening salvo, due to it largely lacking annoying obstacles or stop-and-start level design, meaning that players still got a great first impression. While not as blatant as the UnexpectedGameplayChange Sega included with non-Sonic characters or the initial previews of ''VideoGame/SonicTheHedgehog4'', or spinoffs such as ''VideoGame/SonicLabyrinth'', which was deliberately designed as a [[OxymoronicBeing slow Sonic game]], the seeds were already planted for Sega deviating from the speed Sonic is most known for. Some fans have even pointed out that the alternate character gameplay in ''VideoGame/SonicAdventure'' simply makes it more obvious by segregating the non-speed portions of the classic games into their own campaigns (e.g. Knuckles representing Sonic 3 style ring hunting except with emerald shards, Amy representing block puzzles like Marble Zone).

* A common criticism in recent ''Sonic'' games is the use of automated and {{scripted event}}s over gameplay. However, as some have noted, the use of automated scripted segments goes all the way back to the very beginning (aka, this game), as some zones, such as Green Hill, Labyrinth and Star Light, featured sections in which Sonic goes on a scripted path with little-to-no player input. The difference though was that such segments were usually incredibly brief and non-intrusive, usually only lasting a few seconds at most before giving control back to the player. Later entries, particularly the 3D entries, would have much more elaborate and longer scripted sequences, often taking up larger chunks of the zone and taking control away from the player for much longer, leading to the growth of the aforementioned criticisms.

* ''Sonic 2'' would start the trend of every major title introducing at least one new character, in this case Tails. This initially wasn't a problem since Tails lacked the common writing problems and GameplayRoulette that plagued future characters, but with each game that passed by with a new residential BaseBreakingCharacter or [[TheScrappy Scrappy]], the novelty wore off, and by the mid-2000s any case of adding a new character in the latest ''Sonic'' title [[BrokenBase can make fans lose it]].\\

* The almighty speed booster is introduced in Chemical Plant Zone. Not a problem here, but it caught Dimps' eye, leading to a common criticism of the ''VideoGame/SonicRush'' series and especially ''VideoGame/SonicTheHedgehog4'' being the sheer overabundance of them throughout the game.
* One of the most common complaints about the infamous ''VideoGame/SonicTheHedgehog2006'' was its glitchiness. While nowhere near to the same extent and still being a fairly solid game otherwise, Sonic 2 is also a fairly glitchy game as a result of being ChristmasRushed, even having some [[GameBreakingBug Game-Breaking Bugs]]. For instance, jumping at the end of a level while having all Chaos Emeralds and 50 or more rings [[UnintentionallyUnwinnable softlocks the game, forcing the player to reset and lose all progress]], while landing on certain objects such as the Rexon enemy the wrong way can crash the game altogether.
** Related to the above, a complaint aimed at ''VideoGame/SonicSuperstars'' is how easy it is to get "pinched" (getting just on the edge of a moving block as it's going up next to a wall, thus causing the character to be "pinched" by registering the wall and upward movement as the character being crushed, instead of just being pushed back onto the platform) compared to the classic games. The truth is, starting with Sonic 2, this would be a common glitch/problem in ''every classic Sonic game'' since, ''including'' the beloved ''VideoGame/SonicMania''. The only real difference is the [=3D=] models just makes it easier to notice when it happens.
* A major complaint about ''VideoGame/SonicSuperstars'' is how [[NintendoHard insanely difficult]] the final bosses of each campaign are. However, a lot of the things people complain about the final boss of the campaigns can be traced back to the final boss of Sonic 2. There are two phases to the fight, both with overly precise hitboxes that make stacking hits difficult. (Metal Sonic can only be hit in the front part of its head as its spines will damage Sonic, and the Egg Robo has two spiked hands that give you only the ''briefest'' of windows to damage it less you instead hit the spikes.) On top of all that, you had to do it ''without rings'', making Sonic a OneHitPointWonder. And if you died, you had to start it ''all'' from the beginning again. The main real difference however is that nether boss actively restricted your movement, so it ultimately came down to your own skill you had developed since the start to avoid taking damage. The final bosses of ''Superstars'' meanwhile have attacks that can actively mess with the level geometry, and in the case of Trip's final boss, an attack that completely immobilizes you that unless you're good at SmashingSurvival, which is basically an instant game over if you get trapped by it. Additionally the final boss of ''Sonic 2'' doesn't spend a lot of time in the background or staying out of your line of attack, so if you know what you're doing, you can take them down fairly quickly. Meanwhile in ''Superstars'' they often have long hit and attacking animations that makes the fights [[MarathonBoss quite long ones]], which makes getting a game over to them all the more punishing.

* The story of ''VideoGame/SonicForces'' is about [[TheBadGuyWins Eggman winning]], and conquering the world with his powerful lieutenant Infinite, who by all accounts is loyal to the doctor. Not only that, Infinite as a FinalBoss fight is [[TheyWastedAPerfectlyGoodCharacter supposedly wasted]] in favor of having Eggman as the final boss. This already happened way back in ''Videogame/SonicCD'', where Metal Sonic conquers Little Planet for Eggman, and is the second last boss battle. ''CD'' however came during a time Sonic games barely had a formula, while ''Forces'' suffered from the [[Videogame/SonicColors previous]] [[Videogame/SonicGenerations three]] [[Videogame/SonicLostWorld main]] games having Eggman as the surprise final boss, in fact, [[ItsTheSameSoItSucks the same boss]].

* One of the most common complaints about the infamous ''VideoGame/SonicTheHedgehog2006'' is that it was [[ObviousBeta too glitchy even for its time]]. This can be seen with this game, which had to acknowledge and pass off the enormous number of glitches for its first half as "[[HandWave diabolical traps]]". Both games also ended up like this due to Sega [[ChristmasRushed rushing development in order to release it by a certain date]]. The difference is that ''Sonic 3 & Knuckles'' had the lock-on gimmick to fix many of its more intense glitches and offered many good qualities even with its previous ObviousBeta state. ''Sonic 2006'' never got a fixed version or patch and many believe that the game would still be bad even if the glitches were fixed due to various [[ScrappyMechanic questionable design and gameplay choices]].
* ''VideoGame/SonicHeroes'' would attract ire for reserving the Chaos Emeralds' GoldenSuperMode for Sonic, but Knuckles and Tails have always received the inferior PowerMakeover--even in ''VideoGame/Sonic3AndKnuckles'', only Sonic ever got the full PowerUpFullColorChange and ExpositoryHairstyleChange; Knuckles and Tails only got PowerGlows. The big difference between the two cases is that in ''S3&K'', each character could earn and use a SuperMode in his own right during their individual adventures, while in ''Heroes'', the PowerUp is restricted to one battle with the RailShooter FinalBoss, ''and'' the preceding cutscene clearly shows only Sonic gets an actual SuperMode; Tails and Knuckles only get golden {{Deflector Shield}}s a moment or two later, as though Sonic were merely lending them power. This naturally undercuts what is ''supposed'' to be the triumphant entrance of supposed friends and equals into battle against the TrueFinalBoss by making it clear that Tails and Knuckles have been demoted to Sonic's backup dancers.
* The combined ''Sonic 3 & Knuckles'' foreshadows much of the franchise's problems with "[[GameplayRoulette alternate gameplay]]" by virtue of introducing characters with powerful aerial abilities such as flight and gliding. The "alternate gameplay" of the [=3D=] ''Sonic'' games is often criticized for feeling out of place with the high-speed intention behind ''Sonic'', forcing players who don't enjoy them to contend with much slower-paced gameplay in order to get to the high-speed gameplay they like. However, the level design of ''3 & Knuckles'' is often noted to be much slower paced and winding compared to the more fluid design of its predecessor ''Sonic 2''. This is because ''Sonic 2'' was designed solely with Sonic's speed and jumping in mind, as Tails' signature helicopter flight in that game wasn't controlled by the player and merely served as a means of getting a [=P2=]-controlled Tails back on screen. ''Sonic 3 & Knuckles'', on the other hand, is designed with supporting Tails' flight, Knuckles' gliding and climbing, and Sonic's lack of such vertical and aerial abilities all at the same time, forcing the level design to implement more slow-paced sections just to keep all three characters "balanced". The alternate gameplay of ''Sonic Adventure'' and beyond was merely a method to keep Tails and Knuckles' signature aerial abilities completely intact as opposed to shoehorning them onto Sonic's stages and allow them to completely break the game, and the lack of other playable characters in later [=3D=] ''Sonic'' games can even be seen as a pragmatic response to the "alternate gameplay" becoming so divisive itself, as it would give the developers a three-way MortonsFork between shoehorning characters onto stages that aren't designed for Sonic's lack of flight or gliding, retiring or nerfing those aerial abilities from the characters in question and angering fans who like them, or bringing back "alternate gameplay" wholesale and angering fans who dislike that.

** Additionally, the cases of Eggman getting upstaged in ''Adventure'' and its sequel still gave the doctor enough relative nuance and context to prevent decay, or at least keep it from going too far. While Perfect Chaos does betray him at the end of ''Adventure'' by destroying Station Square, Eggman's original plan is exactly ''for'' that to happen, but only on ''his'' terms. In ''Adventure 2'', despite being subtly manipulated by [[spoiler:Shadow and Gerald]] over the game, he still shows off some agency in shaping other events himself (e.g. the Prison Island heist, tricking Tails into telling him which Chaos Emerald was the real one) and puts his own effort into defeating the ultimate threat. ''Heroes'', however, has him spend most of the game [[spoiler:locked in a room by Metal Sonic while [[ActuallyADoombot robotic decoys]] are deployed in his place as enemies]], with several of the following games having him be treated as effectively an afterthought to the greater narrative even when he was still being built up as a major villain.

* A very frequent complaint about the side characters being OutOfFocus with [[SpotlightStealingSquad too much focus going to Sonic]] in the more recent games such as ''VideoGame/SonicForces'' started with this game and then carried on to later games along with the anime adaptation ''Anime/SonicX'' due to it receiving criticism that the side characters got more focus and development than Sonic and made him look like a VanillaProtagonist who was being OutOfFocus in his own games where he is the titular character. And now as Sega's attempt to address that complaint, they ended pushing the side characters to the sidelines in more recent games without giving them much characterization and making them suffer from BadassDecay to make Sonic be the one to always save the day without giving them a chance to shine.
* The game started a trend in the series where it began shedding its surreal, cartoon-like tone in favor of a serious, sometimes whimsical [[ShonenDemographic shōnen]] style of plot and writing. While this game's story is rather serious, it wasn't too dark compared to the previous games (most of its darker elements are relegated to FridgeHorror and InferredHolocaust) and its tone and CharacterDevelopment made it far more ambitious than the ''Sonic'' games before it and was well-received. As the series went on, not only did the game's story taking itself seriously became less novel [[OnceOriginalNowCommon after it influenced future games to pursue a similar direction throughout the mid-2000s]] (with some even escalating to similar or grander stakes than what ''Adventure'' did before), but later games tended to lack the CharacterDevelopment and lore building to the original series that made this story work, and the dark aspects were ramped up to the extent that the series was seen as becoming an over the top parody of itself, reaching its apex with Shadow's spinoff game and the highly controversial 2006 game.
* Related to the issues of juggling CharacterFocus among the franchise's roster, while this game didn't quite ''start'' the trend of introducing characters with nothing to do outside of the plot of their original game (which really began with ''[[VideoGame/Sonic3AndKnuckles Knuckles]]''), this game started showing the limitations of that approach with Gamma [[spoiler:dying]] and Tikal and Chaos just {{disappear|s Into Light}}ing. At the time, it wasn't a really big deal, since, again, there was nothing left for these characters to do after their stories ended, but over time, the franchise has accumulated Big (and Froggy), VideoGame/{{S|onicAdventure2}}hadow, [[VideoGame/SonicBattle Emerl, Chaos Gamma]], [[VideoGame/SonicRush Blaze]], [[VideoGame/SonicTheHedgehog2006 Silver, Princess Elise III]], [[VideoGame/SonicStorybookSeries Shahra, Merlina]], [[VideoGame/SonicUnleashed Chip]], and others who are all nowadays just floating around in the margins. While the especially popular Knuckles and Shadow have stuck around in the main cast, this has mostly been accomplished by [[TheArtifact ignoring their backstories]].
* While Knuckles being DumbMuscle with a HairTriggerTemper had been part of his official personality since ''VideoGame/Sonic3AndKnuckles'', this was the first game to really show it, leading to his inevitable {{Flanderization}} during the TurnOfTheMillennium, a situation Knuckles would wallow in for years, to the chagrin of many of his fans. It was more tolerable in this game due to having not been a trend yet and being offset by Knuckles substantially contributing to the fights against Chaos.
* One of the most polarizing elements of ''VideoGame/SonicTheHedgehog2006'' is the character of Princess Elise, who many people remark as looking [[RealisticSpeciesCartoonySpecies incredibly out-of-place next to Sonic and pals]], but realistic human characters had been around since ''Adventure'' without too much complaining. Elise is just the first one to be a major character who regularly interacts with the cartoon animals, which throws the contrast in far sharper relief (and the romantic subtext just makes it even more questionable). And while ''Adventure'' does have realistic humans, the technology demanded they be stylized to a certain degree, and ''Anime/SonicX'' does much the same outside of the games with an anime art style that makes the animal characters and human characters fit together better (though it helps that it's a fish-out-of-water story to begin with, with Sonic and friends being contextually out of place as a plot point). Seventh-gen hardware allowed for a lot more photorealism (which was the game's goal to begin with), which, again, put a spotlight on how poorly they fit in with the cartoon animals. Not helping matters is that, outside the pre-rendered cutscenes, the human characters (with the possible exception of Eggman) fall squarely into the UnintentionalUncannyValley. ''VideoGame/SonicUnleashed'' addresses this sin, however, by giving the humans more cartoonish proportions to better fit in with the funny animals.

* An example related to the story. At the very end of the Hero Mode story, [[spoiler:Sonic is able to use Chaos Control, after seeing Shadow using it earlier in the game, to save himself from Eggman's burning space pod]]. Fans agreed that it was a blatant DeusExMachina at best and AssPull at worst, but accepted it anyway because the alternative would have been [[spoiler:killing off the titular character of the franchise]]. Fast-forward to ''VideoGame/SonicTheHedgehog2006'', and the brand-new character Silver the Hedgehog [[spoiler:is able to use Chaos Control perfectly after seeing someone else do it]], just like Sonic did -- but with the crucial difference that this was ''not'' relegated to a single moment in the ending, but done frequently throughout his story campaign with [[ExaggeratedTrope even less justification]] than in ''Sonic Adventure 2''.
* While the first ''Sonic Adventure'' planted the seeds for the series [[CerebusSyndrome shedding its surreal, cartoon-like tone in favor of a]] [[DarkerAndEdgier serious]], sometimes whimsical Shonen Anime style of plot and writing, ''Sonic Adventure 2'', more than any other game in the series, is truly responsible for crystallizing it. While this game's story is far darker than those of previous ''Sonic'' games, it also features attempts at a stronger narrative and actual CharacterDevelopment that allowed fans to look past that. Later attempts to apply a serious story to the series tended to lack satisfactory narratives and CharacterDevelopment, and without any of the qualities that made the stories of the ''Adventure'' games work, all that was left were ([[ExaggeratedTrope now even more ramped up]]) DarkerAndEdgier aspects that made the series seem like an over-the-top parody of itself, especially with Shadow's spinoff game and the highly controversial 2006 game.
* In the Last Story, Eggman's position as the main antagonist [[spoiler:is usurped by Shadow, due to a twist that revealed Shadow had been manipulating him for his own ends all along]]. While this wasn't a new idea so the novelty had worn off, it was accepted at the time because Eggman was still at quite possibly his most threatening yet (at least in the game continuity), played a very active role in the plot to the point of being a playable character, was crucial in [[spoiler:saving the day]], and never got defeated or otherwise humiliated by [[spoiler:Shadow]]. Later games, however, would have [[spoiler:Eggman displaced by other villains]] in ways that seriously hurt his credibility as a villain, and the repeated use of this plot device grew stale before long.
* The stage Green Hill Zone has become infamous over the years for being constantly reused as a NostalgiaLevel. This game features Green Hill Zone as a NostalgiaLevel, but it was an optional bonus level as your reward for collecting all of the Emblems, and the stage had not reappeared in a mainline ''Sonic'' title since the first game. When later games reused Green Hill Zone, they had it as the mandatory first level as opposed to kicking off the journey with an original stage, and it reappeared so frequently (it was featured in ''both'' of 2017's Sonic titles, ''VideoGame/SonicMania'' and ''VideoGame/SonicForces'') that fans began to view the reuse of Green Hill Zone [[ItsTheSameNowItSucks with contempt]].
* The existence of the Last Story at all. While the first game planted the seed with Super Sonic's (brief) story, this game codified it, and tends to get the blame for games like VideoGame/SonicHeroes and VideoGame/ShadowTheHedgehog taking this trend [[ExaggeratedTrope up to eleven]] in some questionable ways that can really only be chalked up to {{Padding}}:
** Sonic Heroes: Instead of six distinct characters or two distinct storylines, you basically have the same set of levels copy/pasted with minor difficulty and cutscene adjustments. Not to mention how all four teams can somehow destroy the same boss at around the same time (do they have to wait in line?). It feels like pointless busywork to unlock a final boss that easily could have been put at the end of a single, cohesive storyline that covered all necessary plot points.
** Shadow the Hedgehog: Ten different endings, all of which require a [[KarmaMeter different path]] through the levels to reach. Some are simple and straightforward, while others require huge collect-a-thons with no radar or hints. This would have worked fine with a level select feature -- just load up the stage and pick a different ending. But instead, you have to do ten full playthroughs, all to reach a (canon) Last Story that ''nullifies them all''.
*** On a similar note while both ''Adventure 2'' and ''Shadow'' were advertised with the prospect of giving the player the choice to be good or evil, only to contain a GoldenEnding which nullified this choice. ''Adventure 2'' was given a pass for the strength of its writing which allowed the two prior stories to occur simultaneously and still lead to the Last Story. In comparison, the paths in ''Shadow'' diverge so widely that essentially '''no''' path can lead to the final outcome, making everything beforehand feel like padding, not helped by the fact the gameplay and marketing leaned far heavier into the idea of the player having a choice than ''Adventure 2'' ever did.
* This was the first game where the final boss, the Biolizard, [[GenericDoomsdayVillain had no real personality and is just a generic monster]][[note]]Chaos was similar, but he also has a tragic backstory to make him less generic.[[/note]], but story-wise, most fans accept this because Biolizard is more of an extension of the dead Dr. Gerald Robotnik's will ([[GreaterScopeVillain Gerald is the real villain of the story]]). Later games would use the GenericDoomsdayVillain tropes without an interesting character behind the monster.[[note]]Later games are a somewhat mixed bag in this regard. To go down the list: Metal Overlord in ''Heroes'' suffers from Metal Sonic having literally no characterization previously aside from being Sonic's robotic doppelganger and his "surprise" reveal in the final story does not fix this ''at all''. Mephiles in ''2006'' at least has a personality and characterization, but he basically becomes a non-entity upon fusing with Iblis to become Solaris, who has no personality or character whatsoever. Dark Gaia in ''Unleashed'' and the Time Eater from ''Generations'' falls into this category as well. The End in ''Frontiers'' does provide an impressive BadassBoast but is otherwise a relatively GenericDoomsdayVillain. Alf Layla wa-Layla in ''Secret Rings'' is arguably an extension of Erazor Djinn, who ''does'' have actual characterization. Black Doom's monstrous OneWingedAngel form in ''Shadow'' absolutely avoids this, however, as does the genuinely surprising AntiVillain turn of Merlina in ''Black Knight''.[[/note]]
* While ''Adventure 2'' was not the first game to employ a HiddenAgendaVillain--''Sonic Adventure'' had one in Chaos, whose story was explained in {{Flashback}}s--it was the first [[AnotherSideAnotherStory to restrict the exploration of these motives to a specific storyline]]. This was not an immediate problem for Adventure 2 due to there being mostly just {{Two Lines|No Waiting}} of about equal importance to the SecretFinalCampaign[[note]]Knuckles' and Rouge's hunt for the Master Emerald shards being a {{Third Line|Some Waiting}} notwithstanding[[/note]]. Following the success of ''Adventure 2'', however, following games produced increasingly complex storylines and intrigues with an increasing amount of StoryBranchFavoritism determined by how much information they revealed about the [[GreaterScopeVillain true]] [[TheManBehindTheMan villain]].\\

This reached a head in ''VideoGame/SonicTheHedgehog2006'', where Sonic's storyline features him focusing on protecting Princess Elise from Eggman--Shadow's story would then proceed to reveal that all three of them are pawns in a game being played by [[TheManBehindTheMan Mephiles the Dark]], which made Sonic (the star and central character of the franchise) [[DemotedToExtra the least important hero in the game]][[note]]Silver, the third hero of the game, was at least busy dealing with Mephiles' other half Iblis[[/note]].

* ''VideoGame/SonicHeroes'' was the first game to have non-boss enemies that were ''not'' [[OneHitPointWonder One-Hit-Point Wonders]], but instead had varying amounts of HP to deplete, as well as having "combat arena" segments where it was mandatory to defeat enemies to advance further in a stage. However, the idea of having enemies that could take a beating wasn't problematic here because it had mechanics to take the edge off -- a level-up system to make the characters stronger (and thus capable of dealing more damage) and the three-man team system giving each team a "Power" character whose main job was to be the heavy hitter and plow through the big enemies and combat arenas. The next game, ''VideoGame/ShadowTheHedgehog'', kept the beefy enemies and ditched the team system, but compensated in its own way through its weaponry system, and the later stages with the beefiest enemies also tended to have the strongest weapons that could easily shred their health meters. While the weapons did have limited ammunition, there was practically always more than enough to kill everything in the stage with as long as you held your fire while there were no enemies in sight. ''VideoGame/SonicTheHedgehog2006'' is where the beefy enemies and combat arenas became problematic, as all three core characters (and the six Amigo characters) had ''much'' worse DPS than in ''Heroes'' and ''Shadow''. Sonic was restricted to laggy Homing Attacks, Bounce Bracelet bounding, and grounded spin-kicks, making his DPS flat-out ''mediocre'', and he had absolutely no way to improve it. Shadow and Silver fared better in the DPS department, being able to attack at a faster pace than Sonic to deplete big enemies' health bars a little more quickly; Shadow's fighting style was literally a better version of Sonic's, with a mid-air combo system allowing him to lock on to an enemy and pummel them several times in quick succession, while Silver relied on using his psychokinesis to pick up nearby objects and fling them at enemies, which he could do at a fairly rapid pace as long as he had enough objects to throw and enough energy to pick them up. Shadow and Silver also had ways to improve their DPS even further -- Chaos Boost and vehicle-mounted weapons for Shadow, and stronger objects such as explosive crates and spike balls for Silver -- but lacked consistent access to their improved DPS. The end result was what was once a minor flow-killer now made level progression a nigh-unbearable slog. Thankfully, Sega listened to the fans' dissatisfaction and have largely dropped both beefy enemies and combat arenas; both made a single major encore appearance in the nighttime stages of ''VideoGame/SonicUnleashed'', where it actually made ''sense'' for them to be present due to the slower-paced BeatEmUp gameplay style, and the daytime stages of ''Unleashed'' and all stages of subsequent games[[note]]aside from the ''Sonic Boom'' games, which had multi-character combat like ''Heroes'' and a more BeatEmUp-esque style like ''Unleashed''[[/note]] have gone back to having all non-boss enemies be destroyed with just one attack. (Beefy enemies and combat arenas are also present in ''VideoGame/SonicFrontiers'', but once again, it makes sense to have them due to the WideOpenSandbox gameplay style, and Sonic has been given access to a wide variety of powerful and/or rapid-fire attack options to deal with the tankier enemies.)
* A complaint about the ''VideoGame/SonicRivals'' series is that the characters [[LetsYouAndHimFight were always picking fights with each other despite having the same goal]]. This happens in this game as well. Aside from the Team Sonic vs. Team Rose battle (which is due to Amy's {{Flanderization}}), however, the battles are a bit more justified by Team Sonic and Team Dark still having an antagonistic relationship while Team Chaotix are strangers to Team Dark and Team Rose.
* While the game's focus on combat was criticized for a variety of {{Scrappy Mechanic}}s (too frequent, too plodding on account of enemy lifebars and/or the level system, slippery controls), most players could deal with the constant breaks in the platforming action to some degree, as the game was designed around utilizing the [[CompetitiveBalance respective strengths]] of [[SuperSpeed each]] [[{{Flight}} team]] [[SuperStrength member]] and most stages were still generally fast-paced enough ([[MarathonLevel despite their length]]) to prevent the issue from becoming ''too'' grating. When later games (''[[VideoGame/SonicUnleashed Unleashed]]'' and especially ''[[VideoGame/SonicBoom Rise of Lyric]]'' [[note]]other titles like ''VideoGame/ShadowTheHedgehog'' and ''VideoGame/SonicAndTheBlackKnight'' also count to a degree[[/note]]) featured an even greater imbalance of combat sections that proved even more monotonous and frustrating, fan reception was not nearly as kind.

* This game introduced the boost mechanic, which would later become a staple of the 3D games, starting with VideoGame/SonicUnleashed. The mechanic here did have its detractors at the time due to it allowing the player to gain maximum speed with a press of a button (whereas previous 2D Sonic games generally focused more on building momentum through skillful play), it was still regarded as a fun and novel mechanic, especially since the 2D format still allowed for varied level design without making the player feel like they were on rails. Unfortunately, this was ''not'' the case for ''Unleashed'', which, while it was still a breath of fresh air and an improvement over its [[VideoGame/SonicTheHedgehog2006 disastrous predecessor]], the boost came under particular scrutiny due to the ''significantly'' more linear level design and Sonic's movement mechanics making the game at times feel like it was basically on rails (and not just when Sonic was literally on rails, either), which made the boost feel to many like an even more mindless mechanic with little actual depth for most players outside of speedrunning. ''VideoGame/SonicColors'' having significantly less 3D gameplay that was largely very linear did not help things any. ''VideoGame/SonicGenerations'' did improve on making Modern Sonic's gameplay feel less linear, but at that point some players had felt the "boost formula" had worn out its novelty and was basically a one-trick-pony that struggled to provide actual gameplay variety, and the boost mechanic itself arguably contributed to this problem. The mechanic is still around as of ''VideoGame/SonicFrontiers'', but it's telling that it's been nerfed to be unable to damage enemies and in the same game most players will use the Spin Dash instead once they unlock it.

* ''Unleashed'' drastically cut down on the amount of characters that appeared with almost everyone being DemotedToExtra. As having huge amounts of characters in each game that took too much focus away from Sonic (whether through [[SpotlightStealingSquad story]] or [[GameplayRoulette gameplay]]) was a common complaint about many previous entries, this was seen as a breath of fresh air. Later games continued to leave the majority of the cast OutOfFocus and kept Sonic as the sole playable character, and without the novelty of having solely Sonic for the first time in years and the lack of gameplay variety becoming apparent, fans began to clamor for the supporting cast to get some love again.
** In addition, while Colors would build on what it started, Unleashed in many ways was the first major post-06 Sonic game to have a simpler story compared to prior games, something that was considered to be a necessary step to make given the issues with Sonic's cast at the time. However, it was balanced out by having a lot of strong world-building and minor characters to provide Sonic and Chip someone to bounce off of as sidequests, thus ensuring that things wouldn't get too boring even if the plot was simple, as well as keeping the world lively and fleshed out even if Sonic's friends weren't around. Most subsequent stories after Colors however ''didn't'' have these kinds of characters, instead either keeping [[DemotedToExtra Sonic's friends around in a limited capacity]], or just having only Sonic and the new antagonist of the week to deal with alongside Eggman. This had the detrimental effect of making the story feel very small and narrow even if the intent or storyline was meant to be more epic, and left the games with only a very barren or shallow plot with little to complement it.
* This game featured a mix of 2D and 3D to address Sonic's growing pains with the [[VideoGame3DLeap 3D transition]]. The 2D segments are rather brief, and the two types of gameplay integrate seamlessly. It also plays around with the camera a lot in these 2D sections. Later games like ''Colors'' and ''Forces'' featured far longer 2D segments in far more abundance, and 3D Sonic games consisting more of 2D than 3D soon became a common complaint.

* The egregious amount of pop in ''VideoGame/SonicFrontiers'' has become one of the most widespread criticisms from fans and critics. However, the Hedgehog Engine has always had trouble with draw distance and pop in as far back as ''Unleashed''. The difference is that in previous games that used the Hedgehog Engine, the camera was locked in place most of the time, which, combined with the linear level design, hid the pop in and made it out of view most of the time. In ''Frontiers'', however, the levels are non-linear and the camera is mostly unlocked and movable (outside of some platforming segments, some of the boss fights and the Cyber Space levels), which, as a result, exposes the pop in that would've been hidden in past games.

* The concept of Wisps in general supplanting the more traditional power-up monitors and character-specific abilities and equipment has left a sour taste in the mouths of a lot of fans, with Sonic Team's reasoning for them still being around amounting to basically [[HandWave "They're around because they like Earth."]] not helping smooth it over at all. ''VideoGame/TeamSonicRacing'' provides the more reasonable excuse for the Wisps' involvement that Dodonpa collaborated with them in order to build his cars and set up the tournament, though it didn't do much to warm the Wisps up to those who were already sick of seeing them.

* When ''Sonic Origins'' had its proper reveal, it received ire for the website's confusing table showing the different versions in a confusing manner. ''Sonic Colors: Ultimate'' originally did the same on the website. It didn't gain much ire, however, due to only comparing the standard and digital deluxe editions, while ''Origins'' featured the DLC packs as well leaving fans to believe there were five versions of the game rather than two.

* Many point to Issue 50 as the moment the series started going downhill, mainly because it [[KilledOffForReal killed off its main villain]]. Issue 50 was meant to be the GrandFinale for the comic, so killing Robotnik was the natural conclusion. However, the comic was renewed at the last minute, [[PostScriptSeason resulting in a general lack of direction]]. Though "The Big Goodbye!" (and its revised version, "For Whom the Bell Tolls") is seen as a lot better than what came after, there's a reason why ''Sonic'' fans [[BrokenBase argue]] over whether or not it was one of the last good stories during Ken Penders' tenure as one of the lead writers, [[AudienceAlienatingEra or one of the first bad ones]].
* The ''Knuckles'' comic was another problem, with Penders deciding not to expand on clues left behind in the video games at the time--indeed, he claimed to have never played the games before joining the comic. Instead, he used the comic more to [[WorldBuilding world-build]] a society of echidnas, mostly because Sega wouldn't let him get away with anything like that with Sonic himself, but they completely ignored what he was doing with Knuckles, giving him carte blanche to do basically whatever he wanted. It worked out for a while, mainly because it helped flesh out the comics' world and the stories themselves were good enough. It also gave Knuckles and the echidnas much needed focus in Archie when he got DemotedToExtra in the later games. After ''Knuckles'' merged back into ''Sonic'', though, [[SpotlightStealingSquad Knuckles' story was given an increasingly heavy focus while Sonic's fell by the wayside, even though the comic was named after the latter.]] All of this culminated in the "Great Harmony" subplot, where Knuckles is proclaimed [[TheChosenOne The Avatar]], one of two heroes prophesied to bring about the eponymous event, while Sonic is just "another champion". This CreatorsPet mentality towards echidnas would eventually cause Penders to trigger the lawsuit that helped kill the comic entirely, though in this case it was Penders himself getting an oversized ego and burning every bridge in the process.

* The ExecutiveMeddling was there from the beginning, with Creator/{{Sega}} executives having a role in what gets produced, the earliest true flex of their influence dates to the uncancellation of the comic at issue 50. They allowed Robotnik to be killed off, but mandated Ken Penders to undo the other major death of the issue, that of Sally Acorn. Since Sally's death had been widely criticized for the way it was handled, this was and still is generally seen as a positive move. However, by the time the comic was canceled, this had blown up to the point that there were ''entire mandates'' on how the comic should be written[[note]]arguably due to the aforementioned Ken Penders having too much ProtectionFromEditors and eventually driving everything OffTheRails and [[ScrewedByTheLawyers throwing a highly destructive legal temper tantrum]][[/note]]. This criticism followed to the [[ComicBook/SonicTheHedgehogIDW IDW comic]], due to the comic being ''even more'' editorial-driven, and introducing highly unpopular mandates (such as game characters [[TheBusCameBack who returned from a two-decades long real-life absence in]] ''VideoGame/SonicMania'' [[ExiledFromContinuity no longer being allowed to be used]], while previously, they were recurring Archie characters in spite of the game canon having them on a LongBusTrip at the time).

** Related to the above; the ''abundance'' of characters as well. Almost ''every'' game introduced a new major recurring character, starting with Tails (Sonic 2), Amy and Metal Sonic (Sonic CD), and Knuckles (Sonic 3). Initially, these characters were rather popular and considered fresh additions (and because of the GrandfatherClause, you'll find very few who hate these four in particular) that added to Sonic's world. But these characters became increasingly numerous, and started to overshadow Sonic himself, and were often tied to questionable gameplay styles. Public opinion started to turn against them, and fans demanded for the cast to be cut down, which led to the aforementioned era of having Sonic as the only playable character.[[note]]Barring sports spinoffs such as the ''Olympic Games'' series that crossed over with ''Franchise/SuperMarioBros'', which allowed for the other Sonic characters to be playable.[[/note]] The only games to actually avoid the trap of too many playable characters and/or the GameplayRoulette problem are ''VideoGame/SonicMania'' and, strangely enough, ''VideoGame/SonicAndTheBlackKnight'', of all games - the latter's surprisingly classic-style implementation is largely overshadowed by its main issues, but the example ''Mania'' that set is often cited as what Sonic Team should've been doing all along in this regard.

* The existence of the Last Story at all. While the first game planted the seed with Super Sonic's (brief) story, this game codified it, and tends to get the blame for games like VideoGame/SonicHeroes and VideoGame/ShadowTheHedgehog taking this trend [[ExaggeratedTrope up to eleven]] in some questionable ways:

* This was the first game where the final boss, the Biolizard, [[GenericDoomsdayVillain had no real personality and is just a generic monster]][[note]]Chaos was similar, but he also has a tragic backstory to make him less generic.[[/note]], but story-wise, most fans accept this because Biolizard is more of an extension of the dead Dr. Gerald Robotnik's will ([[GreaterScopeVillain Gerald is the real villain of the story]]). Later games would use the GenericDoomsdayVillain tropes without an interesting character behind the monster.

* This game is considered to be the start of Tails' BadassDecay, due to the scene where he gets easily frightened by some Nightmares despite fighting greater threats before. Even then, this segment is rather brief and could be written off as Tails being scared of something he knew little about rather than being unable to fight (The fact that Nightmares can seem very similar to [[WhyDidItHaveToBeSnakes ghosts could also help explain why Tails]] acted the way he did. Many later games have far more segments in which he needs to be saved by Sonic, the most infamous being a scene in ''Forces'' where he cowers in fear at Chaos 0, despite [[VideoGame/SonicAdventure previously fighting the more powerful Chaos 4 and witnessing his more powerful forms]].

* This game is considered to be the start of Tails' BadassDecay, due to the scene where he gets easily frightened by some Nightmares despite fighting greater threats before. Even then, this segment is rather brief and could be written off as Tails being scared of something he knew little about rather than being unable to fight. Many later games have far more segments in which he needs to be saved by Sonic, the most infamous being a scene in ''Forces'' where he cowers in fear at Chaos 0, despite [[VideoGame/SonicAdventure previously fighting the more powerful Chaos 4 and witnessing his more powerful forms]].