[[caption-width-right:350:''[[SuperSpeed Super Speed!]]'' ''[[SceneryPorn Super Graphics!]]'' ''[[MascotWithAttitude Super Attitude!]]'']]

->'''''Think Fast.'''''\\\
''Címon faster. Because here comes Sonic The Hedgehog[==]ô. Heís the fastest critter the world has ever seen, and heís a hedgehog with major attitude.''\\\
''Watch him smirk in the face of danger as he blazes his way through hilly pastures, underwater caverns, marble ruins, strange cities and a cybernetic world of enemies in a race to save his buddies.''\\\
''Sonicís got everything a hedgehog could ever want: tricks, gadgets and speed. So donít blink or you just might miss him.''
-->-- Magazine Ad for [[http://s.ecrater.com/stores/236921/4f0a53afe3f4f_236921b.jpg the game.]]

''If you're looking for the 2006 game of the same name, go [[VideoGame/SonicTheHedgehog2006 here]].''

The game that started it all. The game that marked the beginning of Creator/{{Sega}}'s beloved ''[[Franchise/SonicTheHedgehog Sonic the Hedgehog]]'' franchise and one of the most iconic games of the [[UsefulNotes/The16bitEraOfConsoleVideoGames 16-bit era]] [[MyFriendsAndZoidberg and]] its 8-bit counterpart, both released in 1991.

At the beginning of the story, [[BigBad Dr. Ivo Robotnik]], also known as [[IHaveManyNames Dr. Eggman]], has just gone mad (or maybe he already was) and is stuffing the tiny, innocent animals of South Island into his army of robots known as Badniks. Unfortunately for Robotnik, there's one problem. A problem that has blue fur, stands a little over three feet tall, is really quick on his feet, and possesses an "attitude" that will drive foes insane: Sonic the Hedgehog.

Indeed, Sonic is far too fast and big to be caught and used as an organic battery, but thanks to his sense of doing the right thing, he's not gonna just pretend nothing is happening. With only his razor sharp quills and [[MeaningfulName Sonic]] [[SuperSpeed Speed]] as his weapons, Sonic makes it his mission to free his less humanoid pals and confront the mad doctor himself.

On a side note, this game received two obscure tie-in comics: a three-part Japanese manga whose first volume is believed to [[AdaptationFirst predate]] the release of the game, as well as a [[ComicBook/SonicTheHedgehogPromoComic one-shot American comic]] released months later which provides a very offbeat origin story for our spike haired hero.
[[AC:The [[UsefulNotes/The16bitEraOfConsoleVideoGames 16-Bit]] Version]]

The first version, released for the [[UsefulNotes/SegaGenesis Sega Genesis/Mega Drive]].

It practically introduced super speed to the [[PlatformGame platforming genre]] with its eponymous character, which the designers took advantage of by adding obstacles such as loops and slopes. In addition to praise for its innovative gameplay, gamers were also astonished by the impressive graphics, as well as the catchy soundtrack by Masato Nakamura of the Japanese pop group Dreams Come True. ''Sonic the Hedgehog'' put the Genesis on the map and was a catalyst for the console dethroning the mighty Creator/{{Nintendo}} with a 65% market share over the UsefulNotes/SuperNintendoEntertainmentSystem during the 16-bit console wars.

The Chaos Emeralds in this version are obtained via entering the Special Stages and collecting one without hitting the "GOAL" bumper.

''Sonic the Hedgehog'' was [[VideoGameRemake remade]], completely from scratch using a new engine, in 2013, for [=iOS=] and Android devices in HD with proper widescreen support. Like ''[[VideoGame/SonicTheHedgehogCD Sonic CD]]'' before it, it was developed by [[PromotedFanboy Christian "The Taxman" Whitehead]], though this time in collaboration with [[PromotedFanboy Simon "Stealth" Thomley]]. Not only does it let Tails be playable (and even follow Sonic, unlike in ''Sonic CD''), but it finally does what the Lock-On Technology of ''[[VideoGame/Sonic3AndKnuckles Sonic & Knuckles]]'' failed to do and what had once only been possible in an unofficial [[GameMod ROM hack]] created by the aforementioned Stealth: make Knuckles playable.
!! Tropes used by this version:
* ActionBomb: [[ExactlyWhatItSaysOnTheTin Bombs]].
* AmericanKirbyIsHardcore: Sega of America edited Sonic to look more "punk"-like, such as changing his quills to look like a mohawk and giving him a more "angry" expression. It should be noted that this more closely matches his appearance on the title screen, which is the same in both Japan and America.
* AdvancingWallOfDoom: The lava flow section in Marble Zone Act 2.
* AirborneMook: Buzz Bombers. Thankfully, they fly low enough to be easily dispatched.
* BonusStageCollectables: There are six [[BonusStage Special Stages]] each leading to a Chaos Emerald, with ten chances to enter one. If all of them are collected in a single playthrough, the ending is changed slightly. There was no real context for them originally, but they were made more important in the Japanese manual and subsequent games.
* BookEnds: The game's story begins and ends in Green Hill Zone. The same goes with the end credits.
* BossArenaIdiocy: The Star Light Zone's boss would be unstoppable if not for the seesaws Robotnik keeps dropping his bombs onto. The seesaws can either be used to [[HoistByHisOwnPetard throw the bombs back at him]] or the bombs can act as counterweights to propel Sonic up to hit him directly.
* BossArenaUrgency: Spring Yard Zone's boss has a spike on its base, and one by one removes the bricks that make up the floor of the arena; this continues until you defeat the boss, or lose all your footing and fall down the BottomlessPit below. Or defeat the boss, and then [[KaizoTrap carelessly tumble to your death as you go to exit the stage.]] [[YetAnotherStupidDeath Yep.]]
* BossOnlyLevel: The final fight against Robotnik is in a separate level from Scrap Brain Zone Act 3 called the Final Zone, though it takes place in Act 2's terrain and is effectively the Robotnik fight for the Zone.
* BrutalBonusLevel: The 2013 remake has a hidden seventh Special Stage, accessible only from the Level Select (either by selecting it manually or enabling Seven Emeralds mode). Said Special Stage is much harder than any of the other six.
* CharacterTitle
* CheckPointStarvation: The only checkpoint in the whole Star Light Zone is set before the stage's boss.
* ComicBookAdaptation:
** The aforementioned [[ComicBook/SonicTheHedgehogPromoComic promo comic tie-in]], which was also included in some older comic books, as well as magazines like ''Sega Visions'' and ''Disney Adventures''.
** Issues 10 and 11 of the ''Comicbook/SonicX'' comic book featured a two-part story to [[MilestoneCelebration commemorate the game's 15th anniversary]], in which Dr. Eggman traps Sonic, Tails, Knuckles, Amy, Rouge, Cream, Cheese, and Vanilla in a virtual reality world resembling the levels from this game. More recently, the first half of the Genesis arc in [[Comicbook/SonicTheHedgehog the regular Sonic comic]], featured in issues 226 and 227, depict Sonic, Sally, Antoine, and Rotor making their way through the game's stages.
** Averted in ''[[ComicBook/SonicTheComic Sonic the Comic]]'' and some of the [[ComicBook/ArchieComicsSonicTheHedgehog Archie comics]], which began too late to do a proper adaptation; instead, when they need to refer to the game's events, they simply tell readers to play the game for themselves (meaning it takes place in both the game only, Fleetway Editions, and Archie Comics continuities).
* ConvectionSchmonvection: In Marble Zone, Sonic can get within mere inches of boiling hot lava without breaking a sweat. In fact, if an animal is freed from a badnik, such as a seal, they'll hop or swim ''right through the lava''.
* CreditsMedley: Embraced here. The 8-bit version has a mostly original piece of music with just a snippet of the Green Hill BGM.
* DroughtLevelOfDoom: {{Final|Boss}} [[BossOnlylevel Zone]] has no rings.
* DummiedOut: There are several things that were meant to appear in the original version of the game. These elements were later included in the Debug Mode for the 2013 remake:
** A boulder chase in Green Hill Zone. In the final version, the boulder sprites were only used for Robotnik's wrecking ball contraption.
** Swimming goggles for the Labyrinth and Scrap Brain Zones.
** A rabbit Badnik named Splats.
** [=UFOs=] that would fly in the skies of Marble Zone.
* EarlyInstallmentWeirdness: There are several things that sets this apart from the later titles in the series:
** The Spin Dash doesn't exist.[[note]]In the original Genesis version; ''VideoGame/SonicJam'' for the UsefulNotes/SegaSaturn, ''Sonic the Hedgehog Genesis'' for the UsefulNotes/GameBoyAdvance, ''3D Sonic the Hedgehog'' for the UsefulNotes/Nintendo3DS, and the 2013 remake added an option to use it.[[/note]]
** With the exception for the Final Zone, there are three rather than two Acts per Zone. This can make them seem overly long to someone who played later games first.
** Getting 50,000 points doesn't grant an extra life in the original revision (it does in the 8-bit version).
** There are two Zones (Marble and Labyrinth) that you can't just rush through and have to go really slow.
** The same Badniks appear in multiple levels, instead of each level having its own unique set.
** There are only six Chaos Emeralds to collect, and you can't turn into [[SuperMode Super Sonic]].
** There's a speed cap when you're running, as long as you hold forward; rolling is usually the only way to move faster.
** The "spike bug":[[note]]Which was actually deliberate.[[/note]] in this game, if you touch spikes during MercyInvincibility, it wouldn't count and you would still get killed. If you got hit by spikes and fell back onto more spikes, you would die. Such behavior was removed in [[VideoGame/SonicTheHedgehog2 the sequel]] and all subsequent games.
** Sonic and Robotnik are the only characters.
* EasterEgg: Among the hidden content in the 2013 remake are many of the objects that were originally cut from the game, such as the wrecking ball hazard from Green Hill, the bunny Badnik Splats, the boulder, the goggles for safe swimming (they now let him stay underwater for longer before drowning) and even the mysterious flying saucers in Marble Zone. All of them are now finished and can be placed in the debug mode. Also available are Super Sonic and a new Special Stage, as well as use of [[VideoGame/Sonic3AndKnuckles elemental shields and the Insta-Shield.]]
* EasyLevelTrick:
** For all the flak it gets for being a slow level, some of the areas in Marble Zone where you have to push a block over the lava pools and ride on it can be cleared by simply jumping over the platforms in the way. Act 3 also features a nice shortcut behind a certain wall.
** Labyrinth Zone Act 1 has a very hidden shortcut that cuts through most of the level.
** Scrap Brain Zone Act 3 has a DungeonBypass right at the beginning of the level that skips almost all of it. It has traps and holes on the way, though, so you'll still have to work for that shortcut.
* EstablishingCharacterMoment: Just look at the page image. The intro establishes Sonic as our MascotWithAttitude.
* EternalEngine: Scrap Brain Zone is this for the first two acts. By the third it becomes a PaletteSwap of Laybrinth Zone.
* EverythingTryingToKillYou: Scrap Brain Zone, big time. Crushers and circular saws over conveyor belts on cramped corridors, temporary platforms close to flamethrowers and bolt shooters, swinging spiked balls on chains, Caterkillers and Bombs lurking around... and the third act is actually a harder Labyrinth Zone!
* ExactlyWhatItSaysOnTheTin: Final Zone, the final zone in the game.
* FinalBoss: The final Robotnik encounter in the Final Zone has him in a piston machine with a lightning ball generator on the right. Sonic has to hit the one of the two pistons that has Robotnik in it to damage him.
* GameBreakingBug:
** If Sonic is going too fast as he is rolling through the tunnels on Green Hill Zone Act 1, [[http://www.youtube.com/watch?v=BcIZryqkU44 he will reach the bottom of the screen and die]] as if it were a BottomlessPit. Fortunately, this was fixed in later releases of the game.
** At the end of either Labyrinth Zone Act 1 or 2, if Sonic rolls and pans the camera down after passing the end of level signpost, [[http://www.youtube.com/watch?v=PGNm9Ah4Gl4 the game crashes]] just as it attempts to load the end-of-level text.
** At the end of the final boss fight, it is possible to hit him as his defeat animation is playing. This sets his health counter from 0 to ''[[UsefulNotes/PowersOfTwoMinusOne 255]]'', making the fight {{unwinnable}} given the time limit. It's also possible to [[KaizoTrap jump into the bottomless pit after you defeat the boss]]. Later games would put an invisible block in places like that.
* GameMod: This game is considered fairly easy to ROM hack by fans. One of the earliest and most famous ROM hacks was one that [[http://info.sonicretro.org/Knuckles_the_Echidna_in_Sonic_the_Hedgehog put Knuckles into this game and using palette code alterations to avoid any color changing problems with the game]] that had been an earlier reason why it couldn't be done with ''S&K''[='=]s Lock-On.[[note]]As a result, Knuckles' sprites are now a very darker red color compared to what they are in the other Genesis games.[[/note]] It's widely considered the "holy grail of ROM hacking", due to how it circumvented the color problem ''and'' implemented Knuckles' climbing and gliding ability.
* TheGoomba: Moto Bugs. They're not the most common of enemies, but a Moto Bug is the first enemy you see, and they pose about as much of a threat as actual Goombas (they've overall become something of a Goomba in the series as well, generally speaking).
* GreenHillZone: The grassy tropical fields that open the game are the TropeNamer. When compared to its simpler successors, however, Green Hill is actually rather demanding for a first level. It features a good number of enemies and mechanics, and has platforming over bottomless pits as soon as the second act. To make up for that, it also cuts the player some slack with easily obtainable invincibility items.
* InsistentTerminology: The game's manual refers to any action in which Sonic curls up as the fairly wordy "Super Sonic Spin Attack", in places where "jump" or "roll" would suffice.
* InvincibilityPowerUp: Smash a monitor with three stars in it for temporary invincibility. Sparkly stars trail behind Sonic while the effect is active.
* InvincibleMinorMinion: The "Bomb" robots in the Star Light and Scrap Brain Zones. Even if Sonic has invincibility himself, he just passes straight through them.
* KaizoTrap: It's possible to free the animals at the end of Labyrinth Zone 3 and still die to Robotnik if Sonic runs ahead of him.
* LethalLavaLand: Marble Zone.
* MercyInvincibility: Present, but the "spike bug" could get around it. If you land on a set of [[SpikesOfDoom spikes]], you take more damage if the knock back sends you into another set. This was because the MercyInvincibility only activated when Sonic landed on the ground after taking damage. This was fixed in ports and sequels.
* MoodWhiplash: The sudden transition from the fast paced Green Hill Zone to the much slower Marble Zone made this for first timers in this game or for people who played later ''Sonic'' games.
* MythologyGag: The 2013 [=iOS=]/Android remake has plenty for the hardcore Sonic DummiedOut fan. Poke around the debug mode and you'll find they actually finished and implemented long lost features like the Green Hill rolling wrecking ball on its own which now functions properly, the swimming goggles, which now prolong the time Sonic can spend in water, Splats the robot bunny, and the Marble Zone [=UFOs=].
* NewJackSwing: Spring Yard Zone's BGM was heavily influenced by Music/BobbyBrown's "Every Little Step" and laid the groundwork for later Creator/SonicTeam games to feature more New Jack-inspired songs in their soundtracks.
* NonIndicativeName: You might think that the "goal" lines in the Special Stages are, you know, your goal. In actuality, they result in failure, kicking you out of the Special Stage without giving you the Chaos Emerald.[[note]]Though you do still get bonus points and continues for the rings you collected.[[/note]] This makes slightly more sense if you [[AllThereInTheManual read the manual]], which claims that the "Special Zone is really a trap." [[VoodooShark Which kinda just raises more questions]].
* NintendoHard: Continues have to be earned, Special Stages are confusing and it demands memorization of its stages.
* ObviousBeta: Not so obvious when looked at on its own, but compared to some later versions, the original version mostly sold worldwide can be seen as unfinished, as it is missing a few of the graphical effects (most notably the auto-scrolling clouds in Green Hill Zone and the water ripples in Labyrinth Zone and Scrap Brain Zone), and the level select still uses an unfinalized level order. Certain later non-cartridge versions even rub out the spike "bug" and add Spin Dashing.
* OxygenMeter: Once you go underwater in Labyrinth Zone and Scrap Brain Zone Act 3, you get three warning chimes, then [[ScareChord the music changes]] [[NightmareFuel/SonicTheHedgehog and a countdown starts]]. Get out or breathe in a large bubble before 0 finishes, or you drown.
* PaletteSwap:
** Scrap Brain Zone Act 3 is a palette swap of Labyrinth Zone.
** Also counts as AndNowForSomethingCompletelyDifferent. Apparently, Robotnik built his high-tech factory on top of some ancient ruins he can conveniently dump people who irritate him into.
** Also has some sort of relation to DummiedOut, as they were originally going to have him drop Sonic into something unique, but ran out of time.
* PinballZone: Spring Yard Zone is full of pinball bumpers.
* PopStarComposer: The soundtrack was written by Masato Nakamura of the J-pop band Dreams Come True. Some of their songs reuse themes from the games or vice versa, including the Green Hill and Star Light Zone themes.
* PressurePlate: Present in Marble Zone.
* PurpleIsTheNewBlack: The water from Labyrinth Zone is purple in the palette-swapped version in the game's final main act, and this level is below Robotnik's labs.
* RecycledTitle: The 3D platformer released for the UsefulNotes/Xbox360 and UsefulNotes/PlayStation3, which was [[FanNickname nicknamed]] ''VideoGame/SonicTheHedgehog2006'' by fans. It was also released on the series' [[MilestoneCelebration 15th anniversary]], and suffered from [[ObviousBeta major bugs]].
* RiseToTheChallenge: The drastically rising water level that makes up part of the "boss fight" in Labyrinth Zone Act 3.
* ScareChord: If Sonic stays underwater for too long without catching a breath of air from a bubble, the music will suddenly shift to very tense music that will speed up rapidly towards a crescendo before Sonic dies. The drowning music has become ingrained in fans of the series to the point that most players will admit feeling a slight grip of panic upon hearing the music even if they haven't played the game in years.
* SceneryPorn: One of the game's major selling points was that its scenery was not only awesome but the fact that it could scroll past so rapidly when Sonic was at high speed helped graphically (no pun intended) demonstrate the Genesis' power. The Green Hill and Star Light Zones in particular stand out.
* ScoringPoints:
** In the [=REV00=] version they don't do anything. The [=REV01=] version, an UpdatedRerelease ([[NoExportForYou more common in the Japanese and Korean markets]]), gives extra lives every 50,000 points as in later games.
** The game has a high score system, but there's no table for it, so it's pretty much an afterthought. The fact that several levels are explicitly impossible to beat in under 30 seconds (which gets you a 50,000 point bonus) and two levels that give no points at all (Scrap Brain Zone Act 3 and Final Zone) makes it even more superfluous. Later games would downplay the time bonus aspect (most notably ''Sonic 3 & Knuckles'', where ''none'' of the levels can be beaten in 30 seconds), but they would reward you with Continues if you got a certain number of points.
* SequenceBreaking:
** Green Hill Zone Act 3 has some walls that can secretly be destroyed if you roll into them fast enough, and they can be used to bypass big chunks of the level and save time.
** Marble Zone Act 1 has a spiked chandelier near the end of the course that is impossible to pass until it falls, robbing you of precious time--unless you exploit the knockback damage Sonic takes from touching it, which allows you to get on the upper ledge and bypass it quicker. Not very useful for normal gameplay, but its crucial for speedruns. Marble Zone Act 2 has a peculiar bug where if you stand on the edge of the levels first floating ledge as much as possible and let Sonic sink into the ground with it and jump at just the right frame, his collision detection will go bonkers and it'll cause him to zip all the way past the level and reach the goal, allowing a skilled player to beat the level in ''11 seconds''. You can also use the glitch in Act 3, but it risks killing you if you don't pull it off right, and you still have to fight Robotnik at the end.
** Spring Yard Zone Act 1 has a shortcut where if you use the Speed Up Shoes and a spring, you can bypass the lower parts of the level and thus get to the goal faster. Act 3 has a glitch where if you [[ViolationOfCommonSense crouch and let a certain platform crush you]] in a certain way, it'll push you into the building and allow you to pass by part of the level instead of killing you.
** Labyrinth Zone Act 1 has a shortcut that allows you bypass a large chunk of the level by pressing a switch and then backtracking a little to find a secret platform that carries you to a shorter and ''much'' easier alternate route to the goal. Act 2 has a glitch involving a switch and a stone platform that, if you land on it right as it goes into the wall on the left, it'll push Sonic right to the end of the level.
** Star Light Zone Act 2 has a minor break where, if you stick to the top of the level, you can jump over a building and fall through it past the descending platform, saving you a bit of time. Act 3 has a glitch where you can sink into the ground near the top of the level, which glitches you ahead through a big chunk of the level.
** Scrap Brain Zone Act 2 has a glitch where if you go the trap door pit near the top of the level and fall between the floor and the trap at the right, it'll push you to another part of level and let you finish it quicker. Act 3 has a glitch where, if you let the sliding platform cut off the shortcut, you can make yourself sink into the ground by pushing on the right side of it, which will propel you directly to the end of the level.
* SelfImposedChallenge: Beating almost every level without touching a single ring.[[note]]There are only two levels where it is absolutely impossible to avoid rings; Spring Yard Zone Acts 1 and 3.[[/note]] The challenge is popular enough to where a rom hack, ''OMG The Red Rings'', was designed around it.
* SmashingHallwayTrapsOfDoom: The most notable ones are in Marble Zone, though they make a return in Scrap Brain Zone Acts 1 and 2 (and they move at breakneck speeds here). The final boss fight is mostly this.
* SpringsSpringsEverywhere: The yellow springs give Sonic a good jump height or boost, while the red ones launch him skyward. The Spring Yard Zone has tons of springs all over the place as the level's gimmick.
* SprintShoes: Smash a monitor with a shoe in it for temporarily increased acceleration and speed. Sonic's trademark is the ability to move at high speed, but this takes it to another level.
* TempleOfDoom: Labyrinth Zone and Scrap Brain Zone Act 3 are mazes partly underwater and set in what appears to be an ancient ruin. It's yellowish-gold with green vines and blue water in the main Labyrinth, but Scrap Brain turns the water and vines purple and the scenery white.
* TheStinger: Beat the game without collecting all the Chaos Emeralds, and you will see Robotnik over a "Try Again" sign, juggling those you didn't get. If you get the good ending, Robotnik [[AgitatedItemStomping will furiously jump on a "The End" sign instead.]]
* TrapDoor: Plenty of them in Scrap Brain Zone 1 & 2. One of them actually leads to some rings, but the others are pure traps.
* WhackAMonster: The final boss.
* WordSaladTitle: Scrap Brain Zone manages to be both this ''and'' IDontLikeTheSoundOfThatPlace.
* WreakingHavok: Complimenting the great speed that Sonic could go at was a highly advanced physics engine (for the time) that allowed you to pick up speed from running or rolling down a hill. Best seen in GreenHillZone, where you pick up massive speed from rolling down two S-shaped pipes then get launched into a large pile of rings.
* YetAnotherStupidDeath: A common source is the Spring Yard Zone boss. You defeat Robotnik, then carelessly fall through [[BossArenaUrgency one of the gaps in the floor he made]] to your death, and have to fight him again as a result.
[[AC:The 8-Bit Version]]

Released for the UsefulNotes/SegaMasterSystem and UsefulNotes/GameGear, and anonymously developed by a game company called Ancient. It wasn't so much a port or sequel as it was a [[ReformulatedGame unique alternative]] to the 16-bit version. Due to being on weaker hardware, the high-speed element of gameplay was scaled back quite a bit, and it really didn't help the Game Gear gain an advantage over the Nintendo's UsefulNotes/GameBoy in the handheld market. Nevertheless, it's still pretty fun in its own right, and features a catchy soundtrack of its own composed by Yuzo Koshiro (with some adaptations of Nakamura's material).

Unlike its 16-bit counterpart, Chaos Emeralds are obtained through one of the first two Acts in each Zone. The Special Stages are only for extra lives and continues.
!! Tropes used by this version:
* AirborneAircraftCarrier: Sky Base Zone, the first of many in the ''Sonic'' series.
* AntiFrustrationFeature: The Robotnik fight in Labyrinth Zone takes place underwater. To compensate for this, Sonic can breathe underwater and not drown.
* AutoScrollingLevel: Act 2 of the Bridge Zone.
* BraggingRightsReward: There is a 1-Up monitor in every level. If you break them all, [[spoiler:an extra 1-Up monitor ([[BonusFeatureFailure which you most likely won't need at all, due to your massive amounts of lives]]) is added to the final boss arena.]]
* CoversAlwaysLie: The cover art of the Master System version depicts Sonic standing on a loop despite there being no loops in the 8-bit version.
* DevelopersForesight: Normally if a player beats an Act under 30 seconds, they will get a 30,000 point bonus. But if some player by chance manages to beat a Zone in just 20 seconds flat (only possible in Green Hill Zone Act 1 and Sky Base Act 2), you'll get a jaw-dropping 200,000 point bonus. Beat that same act and Sky Base Act 2 in ''under'' 20 seconds? 300,000 point bonus for you.
* DummiedOut: There's an 8-bit rendition of the 16-bit game's Marble Zone theme in the game's data, along with a sprite for that zone's Bat Badnik.
* EndGameResultsScreen: After the ending, the game tallies your points, adding bonuses for things like finding the Chaos Emeralds and entering Special Stages, and also turns your remaining lives into ''more'' points, all adding up to your final score.
* ExactlyWhatItSaysOnTheTin: Jungle Zone and Bridge Zone. Exactly what they sound like.
* FinalBoss: Two variations depending on whether it's the Master System or Game Gear version. Both have Robotnik in a glass capsule on the right and a lightning ball generator above him, and Sonic needs to break the glass. On the Master System, there's a pair of electric pylons along the floor and ceiling that create a current between them, but on the Game Gear, there's only three flamethrower machines on the ground, and only one of them shoots at a time.
* JungleJapes: [[ExactlyWhatItSaysOnTheTin Jungle Zone]].
* TheMaze: Scrap Brain Zone Act 2 and to a lesser extent Act 3 feature this as a gimmick.
* MissingSecret: Scrap Brain Zone Act 3 has only 99 Rings. Don't waste your time looking for the last Ring to get a 1-Up.
* RatchetScrolling: In the Master System version only, Jungle Zone Act 2. If you jump up to the next platform, you can't jump back down without dying.
* ReformulatedGame: The level designs, physics and boss fights are completely different from the 16-bit version.
* RiverOfInsanity: Bridge Zone.
* {{Sampling}}: Most notably, Music/JanetJackson sampled Bridge Zone's BGM for her hit 1997 single, "Together Again".
* ScoringPoints: They don't do anything, though.
* SequenceBreaking:
** In Scrap Brain Zone Act 2, there's a puzzle involving two doors, with a switch opening the one that cuts you off from the rest of the level, but cutting you off from that door in turn, forcing you to go all the way back. However, if you found the Checkpoint earlier and die on the spot nearby, you'll respawn with the door open for you, letting you finish the level much quicker.
** In Sky Base Zone Act 2, you can finish the level in roughly 15 seconds by simply [[ViolationOfCommonSense jumping straight up around the ships cannons]] and then walking over the top of the level straight to the exit.
* UniqueEnemy: There are two enemies that appear only once. There is a single Burrobot, found in Labyrinth Zone Act 2, and a single Bomb, found in Sky Base Zone Act 2.
!! Tropes used by both versions:
* AutoScrollingLevel: Bridge Zone's second act.
* BigStormEpisode: Sky Base Zone's first act.
* BossOnlyLevel:
** Final Zone is the only "true" BossOnlyLevel in the 16-bit version, as Act 3 of every other Zone has some land and enemies before the boss.
** Sky Base Zone Act 3 (also the final zone) in the 8-bit version. The first four zones play with this by having small platforming/running segments prior to the boss, a tradition that would continue for the other Game Gear games. Scrap Brain does not count since there's no boss.
* BonusStage: The Special Stages, accessed by hitting a giant ring with 50 rings at the end of acts 1 and 2 in every zone except Scrap Brain; this give the player a maximum of 10 tries for 6 Chaos Emeralds.
* DamnYouMuscleMemory: No, [[EarlyInstallmentWeirdness there is no Spin Dashing in either version]].
* DownTheDrain: Labyrinth Zone.
* DubNameChange: "Eggman" to "Ivo Robotnik" (or potentially vice versa, as the Japanese version didn't exist until over a full month later and it has been argued that the name might have been a PermanentPlaceholder), as well as just about all of the Badniks. As of the [[UsefulNotes/SegaDreamcast Dreamcast]] era, [[WordOfGod Yuji Naka]] has stated that Eggman is his nickname or alias while Robotnik is his actual name, which is reaffirmed by his relatives' surname and certain lines later in the series.
* EarlyInstallmentWeirdness: Both games have no Spin Dash, no Super Sonic, and only six Chaos Emeralds. Additionally, while the 16-bit version utilized the classic "get Chaos Emeralds from Special Stages" mechanic, the 8-bit version has a freestanding Emerald hidden somewhere in one of the first two Acts of each Zone.
* EternalEngine: Scrap Brain Zone and Sky Base Zone's third act, the last stage of the game
* ExcusePlot: The entire plot is simply "Dr. Robotnik is kidnapping the animals and trying to take over the island, and Sonic has to stop him!"
* GreenHillZone: TropeNamer.
* InCaseOfBossFightBreakGlass: The final Robotnik bosses in both versions shields him in a glass/metal chute that you just need to jump into when you get a chance.
* ItsAllUpstairsFromHere Jungle Zone's second and third acts and Scrap Brain Zone's second and third acts.
* JungleJapes: Jungle Zone.
* KaizoTrap: The 16-bit version has a bottomless pit after the final boss that you can very easily jump into, while the 8-bit version has the end of the Jungle Zone boss, where you must jump from the tightrope you're on to the capsule on the land (or fall into a bottomless pit). It's actually a fairly tough jump.
* LethalLavaLand: Marble Zone.
* LevelsTakeFlight: Sky Base Zone's second act.
* MascotWithAttitude: TropeNamer, and the [[FollowTheLeader inspiration for dozens of knock-offs]], very few of whom actually had good games.
* TheMaze: Labyrinth Zone and Scrap Brain Zone's second and third acts.
* OneWheeledWonder: Several examples, most notably Moto Bug.
* OrdinaryDrowningSkills: Although at least the Labyrinth Zone has considerably more places where OxygenatedUnderwaterBubbles appear than water Zones in later ''Sonic'' games. Labyrinth Zone Act 3 in the 8-bit version is a rare exception though, you are entirely underwater with no air bubbles and can never drown.
* OxygenatedUnderwaterBubbles: Present throughout Labyrinth Zone and Act 3 of Scrap Brain in the 16-bit version. The bubbles appear to generate less often in the latter.
* PinballZone: The Spring Yard Zone of the 16-bit game, as well as the Special Stages in both versions.
* RewardingVandalism: The monitors scattered throughout the game have powerups, which you get by breaking said monitors.
* RiverOfInsanity: Bridge Zone.
* SkyscraperCity: Star Light Zone.
* TheSpiny:
** The hermit crab Spikes, aptly enough, spikes on its back, making jumping from above useless. If Sonic rolls into one, he'll be fine.
** The caterpillar Caterkiller is similar, but potentially more deadly. It's a caterpillar made of purple spheres, one of which serves as a head while the rest have spikes on top. If Sonic hits it anywhere other than the head, not only does he get hurt, but the spheres it's made of [[MadeOfExplodium go flying]] and there's a chance they will hit Sonic again, probably killing him.
* ThisIsADrill: A few badniks have them.
* UndergroundLevel:
** Half of Marble Zone and Labyrinth Zone.
** The second act of Green Hill Zone and the Labyrinth Zone.
* UnderTheSea: Labyrinth Zone.
* UnderwaterRuins: Labyrinth Zone.
* TheVeryDefinitelyFinalDungeon: Scrap Brain Zone and the Final Zone (an extension of Scrap Brain that is essentially the zone's boss fight) in the Genesis version, and Sky Base Zone in the Game Gear/Master System version
* VillainExitStageLeft: Robotnik always flies away every time you defeat him. But, at the end of the 16-bit version, you get the chance to [[NoNonsenseNemesis destroy his escape pod and leave him for dead.]] In the 8-bit version, Sonic will do it in a cutscene at the end.
* WarmUpBoss: The first boss in both games:
** The Egg Mobile-H (Egg Mobile Hammer Ball) in the Genesis version. It's a contraption that swings a wrecking ball back and forth, but it's rather easy to avoid.
** The 8-bit version is even easier, with Robotnik floating in his regular Egg Mobile to the edge of a screen, slowly descending to ground level, and then [[CollisionDamage trying to ram into you]]. The UsefulNotes/GameGear port's low screen resolution makes it possible for Sonic to jump high enough to hurt Robotnik and defeat him before he even gets the chance to attack you. It's easier than the [[VideoGame/SonicTheHedgehog2 drill vehicle]].