History YMMV / Sonic3AndKnuckles

** & Knuckles.[[labelnote:Explanation]]Playing off the fact that locking ''Sonic 3'' onto ''Sonic & Knuckles'' retitles the game ''Sonic 3 & Knuckles'', fans took to appending the "& Knuckles" suffix to other works' covers. Often crossed over with "[[VideoGame/ShinMegamiTenseiIIINocturne Featuring Dante from the Devil May Cry series]]''.[[/labelnote]]

** Both acts of Sandopolis Zone are really long levels. In particular, the ghosts in Act 2 will get on your nerves after a while. And that's not even getting into the "endless, looping sand slide" part.

* ShockingMoments: Angel Island being engulfed in flames, Sonic being nearly bombed by an airship, Eggman destroying an entire temple, Sonic snowboarding down a tall mountain, Eggman stealing the Master Emerald, and Super Sonic chasing Eggman down through space. And may we say that all this was achieved on the UsefulNotes/SegaGenesis?

* SugarWiki/VisualEffectsOfAwesome: The game demonstrates 2D animation techniques that were unheard of for the [[UsefulNotes/The16bitEraOfConsoleVideoGames 16-bit era]]. Highlights include the incredible pseudo-3D effect in the Special Stages, the water in the background matching up perfectly when underwater, and parallax scrolling that actually makes the backgrounds look like an actual world.

** Sonic's [[ArtEvolution redone sprites for the game]]. Some fans liked the more detailed sprites for Sonic, while others preferred the simpler looking sprites from the previous three games and the prototype and wished they kept them for the final version, if only for consistency.

** The soundtrack getting changed to the Prototype/PC tracks in ''Sonic Origins'' was always gonna receive this reception regardless due to how fond fans are of the Michael Jackson/Brad Buxer tracks, but even fans who don't mind the prototype tracks getting used were unhappy that instead of simply reinserting and polishing up the arrangements from the November 3rd, 1993 prototype, Sega instead used different versions that are highly likely to be from an even earlier prototype. These versions immediately received criticism from the fandom, with many regarding them as being inferior to the arrangements from the leaked prototype, on top of being poor quality in their own right.

** The Egg Drillster Mk. II can be annoying to defeat with Tails alone. While Knuckles faces a entirely different boss and Sonic can hop on Robotnik's head with no problem, Tails must carefully fly towards the lower part of his pod taking care to not hit either the drill in its front or the fire on its back, since his tails are the only part that can cause damage while flying. Oh, and since you cannot gain rings when hit, getting hit twice (or 3 times with a shield) is fatal. Considering that Tails is meant to be the game's de facto easy mode, having such a massive DifficultySpike exclusive to him alone is rather jarring, to say the least. If that wasn't enough, there's no rings in the BossRush in ''Sonic Origins''.

** Of these, the blue Super Emerald course (second from the left) is among the most brutal. There's exactly ''one'' path to take that will result in success (any other route will eventually catapult you back into red spheres you'd previously collected, ending the stage), all blue spheres are in straight lines only (collectable rings are boxed inside bumpers, making it very tricky to jump out, nab them, and then safely jump back in to resume the course), and there is practically no empty space anywhere so you can't backtrack to pick up any missed spheres. Better yet, getting from one track to the next requires you to time your jumps perfectly to launch over to the next one; too late and you'll miss the yellow sphere, too soon and you'll miss the last blue one, which automatically means you've failed the course because, as mentioned, the layout makes do-overs impossible.

** Of these, the blue Super Emerald course (second from the left) is among the most brutal. There's exactly ''one'' path to take that will result in success (any other route will eventually catapult you back into red spheres you'd previously collected, ending the stage), all blue spheres are in straight lines only (collectable rings are boxed inside bumpers, making it very tricky to jump out, nab them, and then safely jump back in to resume the course), and there is practically no empty space anywhere so you can't backtrack to pick up any missed spheres. Better yet, getting from one track to the next requires you to time your jumps perfectly to launch over to the next one; too late and you'll miss the yellow sphere, too soon and you'll miss the last blue one, which automatically means you've fail the course because, as mentioned, the layout makes do-overs impossible.

* ThatOneSidequest: The Blue Sphere special stages in the ''Sonic & Knuckles'' half (which become the special stages needed to get the Super Emeralds in ''Sonic 3 & Knuckles'') are far less forgiving than those in the ''Sonic 3'' half and some of them can be incredibly frustrating, with the stages often having very weird and tricky level design and requiring both quick reflexes and perfect and precise timing in order to clear them, especially if you attempt to go after that perfect bonus. It doesn't help that the special rings in the ''Sonic & Knuckles'' zones are more sparse and harder to locate than those in the ''Sonic 3'' zones (especially after Mushroom Hill), nor does it help that if you fail, they have no chance of respawning until you complete the game, which makes their harder difficulty that much more of a headache. The port in ''Sonic Origins'' does make things a bit more bearable by giving you the chance to retry them at the cost of coins, but it doesn't make them any less frustrating.

** Bigs Arms. While it's definitely a challenging boss, it doesn't come anywhere near the sheer scale of the [[VideoGame/SonicTheHedgehog2 Death Egg Robot]] as a final boss in the original ''Sonic the Hedgehog 3''. Of course, this is somewhat forgivable since ''3'' is technically only the first half of the game, and ''Sonic & Knuckles'' gives the game a proper FinalBoss. It's even easier in Knuckles' version due to being able to glide at the proper height and the Eggrobo attacking Knuckles more often than Robotnik, leaving itself more open.

* FanonDiscontinuity: Not towards the game itself, but the Super Emeralds and Hyper forms. While the canon status of the Super Emeralds and Hyper forms remains unknown (though Iizuka has stated they simply disappeared into another dimension, presumably the special stage dimension), many fans opt to ignore them since future games don't acknowledge them[[note]]this is due to Sonic Team not wanting multi-tier power-ups and to risk devaluing the Super forms. Because of this, most alternative power-ups beyond Super Sonic post-''3 & Knuckles'' are unique forms that only appear once and never again. It wouldn't be until ''VideoGame/SonicFrontiers''' third DLC three decades later that Sonic Team would revisit the idea of [[spoiler:an upgraded Super Sonic in the form of Super Sonic 2/Super Sonic Cyber, but even so, they are treated as enhancements of Super Sonic rather than an outright upgrade like Hyper was, and it was a one-time case, as Sonic [[spoiler:loses the enhanced super form permanently after defeating THE END]][[/note]]. It doesn't help that Hyper Sonic is not present in the original ''Sonic & Knuckles'' game, nor does it help that while the Hyper Sonic ending is the GoldenEnding, the Super Sonic ending contains [[TheStinger a post-credits scene]] leading into Knuckles' campaign, leading fans to conclude that Super Sonic is the "canon" outcome.

* FanonDiscontinuity: Not towards the game itself, but the Super Emeralds and Hyper forms. While the canon status of the Super Emeralds and Hyper forms remains unknown (though Iizuka has stated they simply disappeared into another dimension, presumably the special stage dimension), many fans opt to ignore them since future games don't acknowledge them[[note]]this is due to Sonic Team not wanting multi-tier power-ups and to risk devaluing the Super forms. Because of this, most alternative power-ups beyond Super Sonic post-''3 & Knuckles'' are unique forms that only appear once and never again. It wouldn't be until ''VideoGame/SonicFrontiers''' third DLC three decades later that Sonic Team would revisit the idea of an upgraded Super Sonic in the form of Super Sonic 2/[[spoiler:Super Sonic Cyber]], but even so, it was a one-time case, as Sonic [[spoiler:loses the upgraded super form permanently after defeating THE END]][[/note]]. It doesn't help that Hyper Sonic is not present in the original ''Sonic & Knuckles'' game[[note]]According to Iizuka, the form was only added in ''3 & Knuckles'' as a way to encourage players to do the ''S&K'' special stages[[/note]], nor does it help that while the Hyper Sonic ending is the GoldenEnding, the Super Sonic ending contains [[TheStinger a post-credits scene]] leading into Knuckles' campaign, leading fans to conclude that Super Sonic is the "canon" outcome.

* FanonDiscontinuity: Not towards the game itself, but the Super Emeralds and Hyper forms. While the canon status of the Super Emeralds and Hyper forms remains unknown (though Iizuka has stated they simply disappeared into another dimension, presumably the special stage dimension), many fans opt to ignore them since future games don't acknowledge them[[note]]this is due to Sonic Team not wanting multi-tier power-ups and to risk devaluing the Super forms. Because of this, most alternative power-ups beyond Super Sonic post-''3 & Knuckles'' are unique forms that only appear once and never again. It wouldn't be until ''VideoGame/SonicFrontiers''' third DLC three decades later that Sonic Team would revisit the idea of an upgraded Super Sonic in the form of Super Sonic 2/[[spoiler:Cyber Super Sonic]], but even so, it's still Super Sonic and it was a one-time case, as Sonic [[spoiler:loses the upgraded super form permanently after defeating THE END]][[/note]]. It doesn't help that Hyper Sonic is not present in the original ''Sonic & Knuckles'' game[[note]]According to Iizuka, the form was only added in ''3 & Knuckles'' as a way to encourage players to do the ''S&K'' special stages[[/note]], nor does it help that while the Hyper Sonic ending is the GoldenEnding, the Super Sonic ending contains [[TheStinger a post-credits scene]] leading into Knuckles' campaign, leading fans to conclude that Super Sonic is the "canon" outcome.

** A minor example since the game is rather light on plot, but a good chunk of the game's plot and elements such as the presence of Super Sonic and the Death Egg will likely be lost on you if you hadn't played ''VideoGame/SonicTheHedgehog2'' prior.

* FanonDiscontinuity: Not towards the game itself, but the Super Emeralds and Hyper forms. While the canon status of the Super Emeralds and Hyper forms remains unknown (though WordOfGod has stated they simply disappeared into another dimension, presumably the special stage dimension), many fans ignore them since future games don't acknowledge them at all.

** The Egg Gravitron can be a real pain without the Lightning Shield. When Eggman lowers to pick up the orb, that is the only opportunity you have to hit him, and it's very easy to accidentally take a hit afterward because of the shape of the mech. Also, when he drops the orb, it bounces to the side a bit. Furthermore, you've got to be very careful where you let him drop it because it's possible for him to go offscreen if he's close to the edge of the screen. No rings for you on the BossRush in ''Sonic Origins'' as well.

** Red Eye, the miniboss of Death Egg Zone Act 1, has two phases. It can be rather tricky trying to fight it without getting hit. Other minibosses in this game tend to be easy.