->''An [[MascotWithAttitude attitude]], tons of [[MechaMook enemies]], and a [[TagalongKid running mate]] with the mind of a four year old. (No, it's not another [[TakeThat presidential election]]).''
-->--[[http://info.sonicretro.org/images/2/2c/S2_ElectronicGamingMonthly_Issue41_December1992_Page223.jpg EGM Promo for the game]]

The sequel of the original ''[[VideoGame/SonicTheHedgehog1 Sonic the Hedgehog]]'', and proof that Creator/{{Sega}}'s [[Franchise/SonicTheHedgehog little blue mascot]] wouldn't be going away anytime soon.

This game is notable for introducing Sonic's [[TagalongKid buddy]] Tails, Super Sonic (the eponymous character's Emerald-powered super form), and the Spin Dash technique -- all of which have become series staples. It is the second best selling SegaGenesis game of all time, selling over six million copies, only outsold by it's predecessor's 20,000,000 mark.[[note]]However, most of ''Sonic 1''[='=]s sales came from being a pack-in to the Genesis, with 4 million selling standalone, so ''Sonic 2'' is also the bestselling ''standalone'' Genesis game of all time.[[/note]]

Like its predecessor, ''Sonic 2'' had both a 16-bit and 8-bit version, but unlike its predecessor, both versions had different stories.


[[folder: The 16-bit version ]]

Released for the [[SegaGenesis Sega Mega Drive/Genesis]] worldwide Tuesday, November 24, 1992, a date nicknamed "Sonic [[{{Pun}} 2sday]]" during its marketing campaign.

On a trip to West Side Island, Sonic meets a shy young fox named Miles Prower, nicknamed "Tails" by the other inhabitants of the island based on the fact that he has two tails. Sonic allows Tails to tag along with him when he notices that the fox can keep up with him by rotating his two tails like a jet propeller. Tails is also a surprisingly gifted mechanic for his age, as evident when he curiously examines the Tornado, a biplane Sonic uses to travel to West Side Island.

Meanwhile, Dr. Ivo "Eggman" Robotnik, still smarting from his defeat on South Island, has [[TakeOverTheWorld gone global]]: He's enslaved a new army of Badniks to hunt down the Chaos Emeralds, which he needs to bring his planet-sized space station, the Death Egg, to full power. [[Film/ANewHope Fear will keep the local islands in line, fear of this battle station]]. It's up to Sonic to stop him, but he's going to need help... and a vulpine pilot who made the Kessel run in less than twelve parsecs.

''Sonic 2'' kicks everything up a notch. The gameplay is faster than its predecessor. It features 11 Zones, most of which have two Acts; to compensate for having one Act less per Zone than its predecessor, the Acts here are quite a bit longer. Debuting here is the Spin Dash, a technique where Sonic (or Tails) spins in place, revs up, and takes off as a spinning ball of doom, allowing players to destroy Badniks without having to jump and gain instant speed to go up slopes and loops. Also making its debut is the super form; here, after collecting all seven Chaos Emeralds and gathering 50 rings, Sonic turns into [[SuperMode Super Sonic]], a golden hedgehog who's even ''faster'' than his regular form and possesses a higher jump (as well as [[NighInvulnerability invulnerability]]). The Special Stages were also {{retool}}ed, introducing a "non-stop 3D movement" philosophy that would be embraced by the Special stages of its successors. Thanks to these improvements and additions, ''Sonic 2'' is a massive fan favorite, not to mention the second-best-selling Genesis game of all time (right behind its predecessor, of course). To this day, critics often hail it as the best game in the franchise.

The game is the first part in a three game arc regarding the Death Egg, being resolved in the [[OneGameForThePriceOfTwo bipartite game]], ''[[VideoGame/Sonic3AndKnuckles Sonic 3 & Knuckles]]''.

In 2013, off the heels of the similarly ''Sonic 1'' remake, ''Sonic 2'', and by extension, ''[[VideoGame/Sonic3AndKnuckles Knuckles the Echidna in Sonic the Hedgehog 2]]'', was remade in the Retro Engine by [[AscendedFanboy Christian "The Taxman" Whitehead and Simon "Stealth" Thomley]]. This time, Sonic and Tails's team-up ability from the ''Sonic 1'' remake returns and Tails now has the ability to fly and swim, something that he was unable to do by himself in the original version. The remake also adds a new [[BossRush Boss Attack]] mode and [[spoiler:Hidden Palace Zone, which is hidden where the infamous spike pit in Mystic Cave Zone Act 2 was]]. The two-player mode also underwent a major upgrade. Chemical Plant Zone, Aquatic Ruin Zone, Hill Top Zone, and Oil Ocean Zone are now available, Knuckles is no longer confined to the single-player experience, both players can be the same character, and each player's screen occupies their own device (rather than appearing in a split-screen as in the original).

!! Tropes appearing in this version:

* {{Acrofatic}}: Dr. Robotnik turns out to be this when fleeing Sonic into his giant mecha. How he [[FridgeLogic outruns Sonic]] [[StoryDrivenInvulnerability is unclear.]]
* ActionBomb: Asterons.
* AirborneAircraftCarrier: Wing Fortress Zone.
* AirborneMook: Buzzers (which were [[{{Expy}} based off the previous game's Buzz Bombers]]), Whisps, [[GoddamnedBats Flashers, Aquis]], and everything in the Sky Chase Zone.
* ArtEvolution: [[http://info.sonicretro.org/images/5/58/Z_cn05.png The early version]] of the Casino Night Zone looks kinda different.
* ArtificialStupidity: Tails without a second player. To the point where on certain levels, he can spend more time dead than alive despite being invulnerable to enemies.
* AscendedMeme: The infamous spike pit in Mystic Cave Zone Act 2 [[spoiler:is where you access Hidden Palace Zone]] in the Android and iOS remakes.
* BatmanCanBreatheInSpace: As indicated by the end of Wing Fortress Zone, both Sonic and Tails can breathe in space, but not in water.
* BigDamnHeroes: Tails gets such a moment in the normal ending by flying the Tornado near the edge of space to catch Sonic after the Death Egg's explosion. If playing as Tails alone, Sonic gets this moment instead. If all seven Emeralds are collected as Sonic, he goes Super after leaving the Death Egg and flies alongside the Tornado instead.
* BonusBoss: [[spoiler:Featured in the remake's Hidden Palace Zone.]]
* BonusFeatureFailure: Tails is identical to Sonic in every way, with one exception: Unlike Sonic, he cannot go Super (the player couldn't actually control his signature flying ability while playing as him until ''VideoGame/SonicChaos'' [[OlderThanTheyThink and slightly later in 16-bit in]] ''[[VideoGame/Sonic3AndKnuckles Sonic the Hedgehog 3]]'', and he also had a lowered jump height and running speed). The Android/iOS version averts it by including Tails' flight, but you can turn it off via cheat.
* BonusStageCollectables: The Chaos Emeralds are back, and they are collected the same way as before (enter and complete Special Stages). This time, however, there are seven of them, and to access the Special Stages, you now have to pass a check point with 50 rings and enter the portal above it.
* ButtMonkey: Tails is, as one "Let's Play" author on Website/YouTube put it, gaming's first meat shield.
** IronButtMonkey: That said, the kid can shrug off anything, rotoring his way back into the action even if he was just ''killed'' seconds before.
* CasinoPark: Casino Night Zone.
* CharacterSelectForcing: Downplayed, but when playing alone, the default "Sonic and Tails" option is a little more difficult than playing either of them alone. In the Special Stages, you need more rings to succeed, and the computer Tails is very unlikely to make up the difference. It's also possible to put Tails in front in these stages, which is not good. Outside of Special Stages, Tails is liable to hit Robotnik at the worst possible time, causing Sonic to go through him, which is particularly deadly in the Chemical Plant Zone encounter. Also, Tails Alone isn't quite as good as Sonic Alone in the original version, since he doesn't have a super form and doesn't have the flying ability to make up for it.
* CollapsingCeilingBoss: The fight with Eggman at the end of Mystic Cave Zone. The trick is to avoid only the sharp spikes, as the round rocks are completely harmless.
* ComicBookAdaptation:
** Issues 228 and 229 of ''ComicBook/ArchieComicsSonicTheHedgehog'' feature Sonic and Tails, along with Sally, Antione, and Rotor, traveling through some of the game's levels.
** Also, issue 6 of ''ComicBook/SonicTheComic'' had a story in which Sonic and Tails travel through the last two zones of the game in order to prevent the destroyed Death Egg from crashing into the Emerald Hill Zone.
* ContinuingIsPainful: This game is an example in which continuing after something beneficial happens can be painful: once you go into a Special Stage, you come back out with no rings. Thankfully, this isn't the case when playing as Knuckles in the original version of ''[[VideoGame/Sonic3AndKnuckles Knuckles in Sonic 2]]''. In the remake, however, Knuckles also loses all of the rings when he comes out of a Special Stage
* CoolPlane: The Tornado. It even gains a rocket booster in the finale.
* CoOpMultiplayer: Of the tag-along variety; in single player, a second player can control Tails. However, his flight ability can only be used when AI controlled. There is versus mode multiplayer as well.
* CreditsMedley
* CrosshairAware: A crosshair follows Sonic around during the FinalBoss fight when it jumps into the air and tries to land on him.
* CutSong: Track 10 in the game's sound test is an unused and hauntingly good song that was originally meant for Hidden Palace Zone, and ended up unused when the Zone itself was DummiedOut. Even when Hidden Palace Zone returned in the 2013 remake, the song remained unused (the version uses the 2 Player Mystic Cave Zone theme, which is what it used in the beta versions of ''Sonic 2'').
* DisneyOwnsThisTrope: Sega holds patents for the [[http://www.strutpatent.com/patent/054112729/video-game-with-spiral-loop-graphics corkscrews from Emerald Hill]], the [[http://www.strutpatent.com/patent/055133070/video-game-with-switchable-collision-graphics loops from Aquatic Ruin]] which are crossed by an alternate path and also [[http://www.strutpatent.com/patent/054112702/split-screen-video-game-with-character-playfield-position-exchange the teleportation item from Vs. mode]].
* DoWellButNotPerfect: The infamous spike pit in Mystic Cave Zone Act 2 is only really a problem for Super Sonic (and speedrunners). Regular Sonic's jump arc will automatically snag a switch that lowers a drawbridge, while Super Sonic has a bad tendency to swoop through the air too fast and miss it.
* DroughtLevelOfDoom: Death Egg Zone. VeryDefinitelyFinalDungeon. One midboss and the FinalBoss. ''No rings''.
* DuelBoss: The battles at the Wing Fortress and Death Egg Zones, since even in Sonic & Tails mode, Tails is shot down in the Tornado on the way there.
* DummiedOut: A couple of Zones met this fate, most notably the Hidden Palace Zone, of which you can find its rather somber BGM (track 10) in the final version. Hidden Palace Zone finally appears ''[[VideoGame/Sonic3AndKnuckles Sonic & Knuckles]]''. However, the ''Sonic & Knuckles'' version of Hidden Palace looks completely different. The Zone as planned for ''Sonic 2'' [[http://www.joystiq.com/2013/12/11/remastered-sonic-the-hedgehog-2-hits-android-ios-tomorrow-with/ eventually appears on the Android and iOS ports as part of a December 2013 update]], although the 2P Mystic Cave Zone music plays instead.
* EternalEngine: A number of Zones, but most notably Chemical Plant Zone and Metropolis Zone.
* EverythingTryingToKillYou: Mystic Cave Zone and Metropolis Zone.
* EvilOverlooker: Dr. Eggman in the (now-iconic) poster and box art.
* GameplayAndStorySegregation: If you're playing as Sonic and Tails, both characters are present in the Special Stages even during Wing Fortress Zone, where Tails is absent.
* GameBreakingBug:
** Whatever you do, do ''not'' try to turn back into Super Sonic again at the end of a level (where touching a goalpost or capsule cancels out Super Sonic automatically); most of the time, doing so will trap Sonic in mid-air, preventing the game from moving on to the next level, and thus forcing the player to reset the game. It should be noted that is only applies to the first versions of the game. A later revision of the game got released that fixed this glitch, and this version was also used on the ''Sonic Classics'' cartridge.
** Turning into Super Sonic while you complete the Wing Fortress level will leave you unable to finish the level. Super Sonic jumps too high and this causes him to miss the scripted event of Tails' plane flying below to catch him, which in turn causes you to plummet to your death and replay the battle or level again.
* GreenHillZone: Emerald Hill Zone, essentially an even easier variation on the original Green Hill Zone.
* GoldenEnding: The 2013 remake one ups the original ending: [[spoiler:Get all seven Emeralds and, at the credits, you'll watch the Death Egg crash on a certain island and, as Eggman stomps his feet, [[VideoGame/Sonic3AndKnuckles a certain Guardian's eyes peek out of the bushes]].]]
* HailfirePeaks: Several Zones don't fit well into any one category, such as Hill Top Zone (DeathMountain / GreenHillZone / LethalLavaLand) and Aquatic Ruin Zone (TempleOfDoom / halfhearted UnderTheSea). Casino Night Zone is one part CasinoPark and one part PinballZone.
* HumanCannonball: One of the more fun ways of getting around Oil Ocean Zone is to shoot yourself out of the various cannons dotted throughout the level.
* HumongousMecha: [[FinalBoss Dr. Eggman's Giant Mech]], named Death Egg Robot in ''VideoGame/SonicGenerations''.
* HundredPercentCompletion: The "perfect bonus", awarded for picking up (not necessarily retaining) all the rings in an Act. It's not possible in every Act.
* InconvenientlyPlacedConveyorBelt: Metropolis Zone has quite a few.
* ImpossiblyGracefulGiant: Averted by the Giant Mech, who moves rather slowly. Made ironic by Dr. Eggman's running skills shown before the battle.
* InvincibleMinorMinion:
** Crawl in the Casino Night Zone can only be destroyed by spinning or rolling into him from behind: attacks from above or the front bounce harmlessly off his pinball bumper shield. On the other hand, he's fairly passive and if you don't bother him, he won't bother you. An appropriate enemy for the CasinoPark level.
** The Flashers in the Mystic Cave Zone are invincible when lit up (even when Sonic himself has the invincibility power-up, he'll just pass straight through them without destroying them).
* KaizoTrap:
** Sort of. During the boss fight in Chemical Plant Zone Act 2, the ground on either side of the arena flips periodically, sending whatever's on them into the water and the pit just beneath the surface. Since there's probably no hope for you if you fall in, you still have to be careful after the boss is beaten, because the platforms still flip. It doesn't help that said boss is [[WakeUpCallBoss suddenly harder than what little you've already gone through]].
** A ''literal'' kaizo trap can happen [[http://youtu.be/abY5jprIF3E at the end of Metropolis Zone Act 3]]. If you beat the boss as Super Sonic without destroying any of the clone bubbles the boss spawns and then run out of rings before reaching the animal pod at the end of the level, it's actually possible for the clone bubbles to follow you over to the pod and kill you while your end-of-level score is being tallied. Of course, you'd pretty much have to be actively trying for this to happen, so it overlaps heavily with EpicFail.
* LevelsTakeFlight: The aptly named Sky Chase Zone. Despite the mellow groovy background music, and relaxed pace, it's harder than it looks.
* LogoJoke: Sonic rushes to the right, and then to the left, his afterimage revealing the Sega logo, the "SAYYYYYYY-GUH!" from the first game then playing.
* LongSongShortScene: The Death Egg Zone theme is whimsically creepy, catchy, and awesome. However, since it's only played in the corridor before the Mecha Sonic fight, you likely won't even hear 10 seconds of it. This is justified by the fact that it was originally supposed to be played for a full-length Act in the Death Egg Zone, but that was DummiedOut.
* TheMissingno: Messing around in debug mode could turn Sonic's sprite black and green; fans have nicknamed this new "character" Ashura.
* {{Mordor}}: Oil Ocean Zone is a Type 2.
* MythologyGag: The 2013 remake adds [[WesternAnimation/AdventuresOfSonicTheHedgehog a green Grounder]] into the debug mode for Aquatic Ruin Zone.
* NonLethalBottomlessPits: [[spoiler:That infamous spike pit in Mystic Cave Zone Act 2 leads to Hidden Palace Zone in the remake.]]
* NotSoHarmlessVillain:
** The crab-themed badniks in every other ''Sonic'' game, and most relevantly the Crabmeats in ''Sonic 1'', are usually TheGoomba, among the weakest enemies. Then the Metropolis Zone throws the Shellcraker [sic] at you, which looks similar but is ''insanely hard to avoid or kill'' with an incredibly small hitbox.
** The crab/bumper enemies (Crawl) in Casino Night Zone are impossible to defeat from the front or the top because they always block your moves. You have to spin dash them from behind. This has caught a lot of players out.
* OldSaveBonus: If the game is locked on with ''VideoGame/SonicAndKnuckles'', ''Knuckles in Sonic 2'' can be played. This makes Knuckles playable with all his abilities from ''Sonic & Knuckles'' intact. In the 2013 remake, Knuckles is available from the beginning.
* OneHitPointWonder: With no rings available in the final stage, Sonic is effectively reduced to this.
* OxygenatedUnderwaterBubbles: Present throughout Aquatic Ruin Zone.
* PaletteSwap:
** Tails is basically this for Sonic. Despite being able to fly while AI-controlled, you can't do so while playing as him. The only major gameplay difference is that Tails can't go super. [[DivergentCharacterEvolution This was addressed in Sonic 3]].
** Also, Hill Top Zone uses almost the same graphics as Emerald Hill Zone. The only differences being that the ground has blue blocks under the grass instead of brown, it has lava, and it has pine trees instead of palm trees. Loading the game in a tile editor reveals Emerald Hill Zone even has the vines that those blue platforms slide down, and a very early prototype of the game (which appears to be the same one shown on an episode of ''Series/NickArcade'') allows you to place the seesaws from Hill Top in Emerald Hill by using debug mode.
** Emerald Hill Zone and Hill Top Zone were the first two levels designed for the game, and it's not inconceivable that they were supposed to follow one another at one point. Hill Top Zone was also supposed to have a winter version called Winter Hill Zone but this was never implemented into the game. The game developers said they used the same palette to save space, the same reason why they used the Metropolis Zone palette for Genocide/Cyber City Zone (Act 3 of Metropolis), and how in the first game they used Labyrinth Zone's Palette for Act 3 of Scrap Brain Zone.
** It's harder to notice, but the Death Egg Zone uses the same tileset as the Chemical Plant Zone.
** In ''Knuckles in Sonic 2'', the blue background of the zone title cards is green, the Shield is gray instead of blue, and the Flickies are red. None of these color changes are present in the iOS remake of the game.
* PinballZone: Casino Night Zone.
* PopStarComposer: Dreams Come True bassist Masato Nakamura once again, who provided music for its predecessor. Due to financial disagreements between him and Sega, this would be Nakamura's last contribution to the series until ''Sonic 2006'' (where Dreams Come True teamed up with Akon to do a remix of "SWEET SWEET SWEET" and "SWEET DREAMS"). Nakamura's departure resulted in the intro music for ''Sonic Spinball'', originally a metal-esque remix of his ''Sonic'' theme, getting replaced by a different tune, and Sega relying on composers from its Wave Master music studio to write the music for most subsequent ''Sonic'' games.
* PuzzleBoss: [[spoiler: The boss of Hidden Palace Zone, where Robotnik's mobile flies out of reach. You need to wait for Robotnik to summon a large SeaMine, then lure him over it when it explodes into a water column that knocks him down for a while, allowing Sonic to hit him.]]
* SceneryPorn: The second game manages to be even more beautiful than the first, which was already gorgeous as it was.
* SchizophrenicDifficulty: Chemical Plant Zone Act 2 is a lot harder than its position in the game (fourth Act out of twenty) would suggest, and for a while afterwards the game gets quite a bit easier.
* SecretLevel:
** The 2013 remake adds one. [[spoiler:In the original version, there is an inescapable spike pit in Mystic Cave Zone Act 2. The remake removes the spikes and the pit instead leads to none other than the formerly DummiedOut Hidden Palace Zone. Furthermore, the beta version of the level, sad music and all, [[https://www.youtube.com/watch?v=0Xcai3NW7cA is accessible by a code.]]]]
** The remake also has a [[http://www.youtube.com/watch?v=R7qbidxNXy8 hidden Special Stage]] that can be played through the level select menu. It has corkscrews near the end!
* SequelHook: Present in the remake once you've collected all the Chaos Emeralds.
* ShooOutTheClowns:
** When playing as Sonic with Tails tagging along, the Tornado-1 gets shot down at the beginning of Wing Fortress Zone, with Tails inside. Sonic has to face the last two Zones alone.
** Inverted if you're playing as Tails: the Tornado gets shot down with Sonic inside.
* ShoutOut:
** Few American kids might have caught the reference in '92, but looking back, it's hard to observe Sonic powering up to an absurdly high level by sporting gold fur and wildly upright spines (after collecting [[GottaCatchEmAll seven artifacts of power]], no less) and not be reminded of [[Manga/DragonBall a certain anime series]]. Also, that's no moon. It's a [[Franchise/StarWars Death Egg]].
** In another anime reference that no American kids at the time would have gotten, the final boss isn't just any giant robot, it is, in fact, a Scopedog from ''Anime/ArmoredTrooperVOTOMS'' slightly modified to look like Robotnik.
** Not even the cheat codes are immune to this. Due to every sound in the Sound Test being assigned a hexadecimal number, it wasn't difficult for Sega to slip in a couple of extra shoutouts. Using the Japanese date format (year, month, day), the level select code becomes September 17, 1965 (19-65-09-17) - Yuji Naka's date of birth - while the debug mode code becomes November 24, 1992 (01-09-09-02-01-01-02-04); the fabled "Sonic 2s-day" that saw the game's North American and European release.
* SmashingHallwayTrapsOfDoom: Mystic Cave Zone and Metropolis Zone have most of them in this game.
* SpikesOfDoom: Many of them. The most notable one is the inescapable spike pit in Mystic Cave Zone Act 2, which could kill you even if you're Super Sonic by making you wait until you lost all your rings, revert back to normal Sonic, and die. [[spoiler: Said spike pit was replaced by the entrance to the Hidden Palace Zone in the 2013 remake.]]
* SpiritualSuccessor: Several levels follow the same themes as those in ''Sonic 1''.
** The Emerald Hill Zone for the Green Hill Zone.
** The Casino Night Zone is a development on the Spring Yard Zone "pinball machine" theme, to the extent that it's one of the most influential levels on future ''Sonic'' games while all vestiges of Spring Yard were dropped.
** The Metropolis Zone for the Scrap Brain Zone. Both are an EternalEngine, green in color, etc. To the point where people playing ''Sonic 2'' for the first time in 1992 were subject to YourPrincessIsInAnotherCastle when they found out it wasn't in fact the final Zone.
** Aquatic Ruin Zone is this for Labyrinth Zone, due to its use of water and ruins, but is somewhat easier.
* SpoiledByTheManual: Although the English manual stops the level description list at Wing Fortress, it reveals the FinalBoss on page 4.
* SoundtrackDissonance: Despite song hexadecimal 10 commonly referred as Hidden Palace's theme, it is not included in the Android/iOS version, due to the fact that [[https://twitter.com/CFWhitehead/status/411261767046553600 the producers felt the song couldn't fit the pace or prehistoric feel of the level.]]
* TheStinger: The remake has an [[http://www.youtube.com/watch?v=IPVsyR6j_3Y additional ending cutscene]] for getting all the Chaos Emeralds, which hints at a remake for the [[VideoGame/Sonic3AndKnuckles final 16-bit Sonic game(s)]].
* SuperMode: Introduced in this game. Become Super Sonic by collecting all Chaos Emeralds. After that, collect 50 rings and jump. Normally touching enemies hurts Sonic, but as Super Sonic, it ''defeats enemies'' instead. Touching [[SpikesOfDoom spikes]] in Super Mode won't hurt Sonic either, but he can still die by falling in a {{bottomless pit|s}}, being crushed, or drowning. As Super Sonic, Sonic's rings decrease steadily and he turns back into regular Sonic if he runs out. It's only for Sonic though. Tails will have to wait for the next game(s).
* TagalongKid: Sonic's new sidekick Tails.
* ThemeMusicPowerUp: Super Sonic.
* ThisIsADrill:
** Robotnik has two drill-themed contraptions: the drill-tank contraption from Emerald Hill Zone, and the cave-burrowing contraption from Mystic Cave Zone.
** The Grounder Badnik in Aquatic Ruin Zone has two drills for hands and a third for a nose. The Spiker Badnik in Hill Top Zone comes equipped with a detachable spiked drill on its head.
* TubeTravel: In the Chemical Plant Zone and the Metropolis Zone.
* UnderTheSea: Aquatic Ruin Zone is a fairly halfhearted attempt, given that it's quite easy to pass both Acts without going underwater once. It may represent fan backlash over Labyrinth Zone, but annoyed players who didn't automatically view water levels as DownTheDrain. Ironically, you could easily spend more time underwater in the Chemical Plant Zone.
* UnwinnableByMistake: When you finish the stage as Super Sonic (i.e. run past the spinning sign at the end), you immediately power down. If you jump again, you'll transform into Super Sonic, immediately power down, and be stuck running in place in midair. Sonic runs to the right and offscreen when the sign finishes spinning; but if he's stuck in midair, the stage doesn't register as finished and you have to reset.
* VideoGameCrueltyPotential:
** Tails may be immortal, but the level design offers ample opportunity to "kill" him by squashing him with obstacles. This potential became a RunningGag in Cybershell's LetsPlay of this game and ''Sonic 3 & Knuckles'' in retaliation for Tails's ArtificialStupidity.
** This is also the entire point of the Tails abuse Machinima series by Whoisthisgit on Website/YouTube (the ones that use actual gameplay at least).
* WakeUpCallBoss: Robotnik's chemical-dumper contraption from Chemical Plant Zone, the ''second'' Zone. It's not too hard, but the two platforms on both sides of the field periodically collapse into {{bottomless pit}}s, making it very possible for a chemical projectile to knock you into the purple water below. Playing as "Sonic and Tails" also presents its share of problems, as when you jump, so does Tails, and if he hits Robotnik first, you'll go through Robotnik (due to his MercyInvincibility) and down the pit. However, if you actually have a second player to wield the other controller, it becomes laughably easy, since a crouching Sonic is ''immune'' to the boss' attack, and Tails will always respawn if you manage to get him killed.
* WarmupBoss: Robotnik's drill car contraption from Emerald Hill Zone, which goes from one side of the screen to the other. It's even ''easier'' than the wrecking ball contraption from ''Sonic 1'' (which was also the first boss of its respective game).
* WouldBeRudeToSayGenocide: There was an originally planned but deleted Zone called Genocide City. The Japanese developers chose the name because they thought it sounded cool, but then they bothered to look up what the word meant.
* WrapAround: A few parts in Metropolis Zone loop vertically, leading to instances of IFellForHours.

[[folder: The 8-bit version ]]


Released for the SegaMasterSystem and GameGear, this version was actually the ''[[OlderThanTheyThink first]]'' to be released and thus Tails' official debut, although the Genesis backstory is his formal introduction. It was anonymously developed by a game company called Aspect.

Bored after defeating Robotnik a little while back, Sonic leaves South Island in search of adventure. When he returns, he finds most of his animal friends, including his best bud Tails, gone. He finds a letter from Tails, which states that Robotnik is behind the kidnappings, and he's holding Tails ransom for the six Chaos Emeralds inside his lair, the Crystal Egg Zone. Justifiably riled up, Sonic sets off once again to take down Robotnik.

This version of ''Sonic 2'' builds on its predecessor with somewhat faster gameplay, even including loops in one Zone. It also includes some differences from its 16-bit counterpart, such as Zone gimmicks including mine carts and hang gliders, the lack of a spin dash (perhaps due to being this being the first version released), and the omission of Tails as a playable character (for obvious reasons, of course).

Once again, however, the Emeralds are collected in the second act of each Zone, except for the sixth, where it's the reward for beating the penultimate Zone's boss after collecting the first five. Getting all of them grants access to the ''true'' final Zone, the aforementioned Crystal Egg, where Sonic confronts Robotnik in a final battle to save Tails.

It's also the only SMS/GG ''Sonic'' game to ''not'' have Special Stages.

!! Tropes appearing in this version:

* AntlionMonster: The first boss is a robotic antlion. To defeat it, Sonic must dodge the cannonballs that Robotnik throws at him so that they will hit the robotic antlion. Eventually, Robotnik flies down at Sonic and Sonic must dodge him as well so Robotnik will inadvertently deliver the final hit. This boss is harder in the Game Gear version due to the reduced amount of space on the screen.
* BondVillainStupidity: The sequence before the first boss battle can look like this: if Robotnik wants Sonic dead, why did he rescue him at the end of the Underground Zone? To drop him in front of his death trap, of course... but if one remembers the plot of the game, Robotnik wants the Chaos Emeralds. At this point of the game, Sonic is supposed to already have one Chaos Emerald out of six, and Robotnik sure doesn't want it to sink into the lava.
* BossOnlyLevel: Act 3 has no enemies, only some platforming and then the boss. [[OneHitPointWonder There are also no rings in Act 3.]]
* BrightIsNotGood / CrapSaccharineWorld: Crystal Egg Zone, the true final zone of the game, is oddly bright colored and cheerful, with happy music. It is also the inner sanctum of Robotnik, and [[EasyLevelsHardBosses while the zone is fairly easy the boss isn't.]]
* BubblyClouds: Sky High Zone is a mix of this and DeathMountain, as the lower parts of its Acts appear to be a mountain peak and the upper parts are clouds, some of which can be stood on.
* CameraScrew: One of the reasons that the Game Gear version is considered NintendoHard.
* EasterEgg: There is a 1-up hidden at the left side of Sky High Zone Act 1. When Sonic jumps over the monitor, a group of birds will come out of the trees and jump around.
* FloatingInABubble: There are giant bubbles in the second act of Aqua Lake Zone, which Sonic can float in.
* GreenHillZone: Green Hills Zone.
* HostageForMacGuffin: Tails.
* KillTheCutie: [[spoiler:Heavily implied in the DownerEnding.]]
* [[NeverTrustATrailer Never Trust a Level Intro]]: Each level intro segment features Sonic and Tails going through the trials of the upcoming level, but Tails is not a playable character; he is kidnapped.
* NintendoHard: The Game Gear release is considered significantly harder than the Master System's due to a [[CameraScrew smaller resolution]] inhibiting players from being able to see what's ahead, resulting in cheap hits/deaths.
* NoFairCheating: You need all the Chaos Emeralds to get to the Crystal Egg Zone to get the good ending. If you don't have them all (save the one you get from the boss) the game ends there with the bad ending. If you use the level select cheat to get to the Crystal Egg Zone, you'll rescue Tails (he'll appear in the teleporter when Robotnik retreats), but he won't be there in the ending.
* SequelDifficultySpike: Due in part to the lack of checkpoints or shields and the increased length of the still-ringless boss Acts (Green Hills Zone Act 3 in particular has a series of blind jumps over spike pits before you reach the boss), this game is generally regarded as significantly harder than its predecessor, as well as harder than most other ''Sonic'' games from the same era. The Game Gear version adds some difficulty due to the screen displaying a smaller area, but even the Master System version is widely considered difficult by the standards of the series.
* SoundtrackDissonance: In the Master System version, what is the cheery title screen music in the GG version plays in the opening cutscene where Tails is kidnapped by Robotnik, and the melancholic music from the bad ending plays for both endings. The Game Gear version rectifies both cases by using the suitably foreboding Scrambled Egg Zone theme in the opening cutscene and providing happy music for the good ending.
* StarsAreSouls: [[spoiler: During the staff roll credits of the bad ending, Sonic looks up into the sky and sees an image of Tails among the stars. This can be interpreted to mean that Robotnik actually ''killed'' him (although this interpretation doesn't explain why in the good ending Sonic and Tails are both pictured among the stars, while being alive and well).]]
* VillainousRescue: Robotnik surprisingly pulls this on Sonic in Underground Zone Act 3; when Sonic is about to fall into a pit of lava, he hastily grabs him with a claw machine, lifting him up...only to drop him into a boss battle.
!! Tropes appearing in both versions:
* EternalEngine
* EvilKnockoff: Silver Sonic.
* GreenHillZone: Emerald Hill Zone and Green Hills Zone in the 16-bit and 8-bit versions respectively.
* MultipleEndings: [[DepartmentOfRedundancyDepartment As mentioned above]], the ending in the Genesis version changes a little based on who you're playing as and, in Sonic's case, whether or not you got all the Emeralds, though there are [[AvertedTrope no]] {{downer ending}}s or even [[TheStinger stingers]] (though the latter was rectified in 2013 remake). In the 8-bit version, without collecting the first five Emeralds upon defeating the Scrambled Egg boss, the game simply ends there, and you get a total DownerEnding. Unable to save Tails, Sonic is running along a trail while sad music plays, and after the staff roll ends, he halts to look at the sky, where he sees Tails's face in the clouds, implying that [[spoiler:poor Tails was killed]]. The good ending is infinitely more satisfying. Happy music plays (unless it's the SMS version, where it plays the sad music for both endings) as Sonic and Tails run along a trail, and after the staff roll ends, they halt to look at the sky, and see each other's faces in the clouds.
* LethalLavaLand: Hill Top Zone and Metropolis Zone (Genesis), and Underground Zone (8-bit).
* PunnyName: Miles Prower = "miles per hour".
* SequelDifficultySpike: Both games are considerably tougher than ''Sonic 1'' for Genesis and Gear, the Game Gear version of ''Sonic 2'' being particularly more brutal than the original.
* TimeTravel: Was originally supposed to invoke it so that it would be closer in feel to ''Sonic CD'' (which was in development at the same time), but was scrapped at some point in development.
* UndergroundLevel: Mystic Cave Zone (Genesis) the [[ExactlyWhatItSaysOnTheTin aptly named]] Underground Zone (8-bit).
* UnderwaterRuins: Aquatic Ruin Zone (Genesis) and Aqua Lake (8-bit).
* VillainExitStageLeft: In the Genesis version, Dr. Eggman flies away when defeated, as usual. However, when defeated on his giant mech, he goes down with the Death Egg (though as the all-emeralds ending added in 2013 remake shows, he survived and the Death Egg didn't really explode). In the 8-bit version, it's played straight as he escapes after the final battle.
->''[[{{Tagline}} ARE YOU UP 2 IT?]]''