For the original 8-bit game, go to this page.
- Alternate Character Interpretation: In Atomic Destroyer Act 3, Fang joins Knuckles in stopping Rocket Metal Sonic from attacking Sonic and Tails. However, given that he has been nothing but antagonistic towards the duo prior, it is possible that he wasn't attacking Metal Sonic to save Sonic and Tails, but rather, it was because Metal Sonic had stolen the Dark Emerald from him earlier on and he wanted payback.
- Anti-Climax Boss: While Fang is not a deceiving boss by himself, you would expect something more tense than just his three boss fights in a row for the end of Knuckles' campaign. Fortunately, the final content update to the game expands on this, bringing in a new boss fight against both Metal Sonic and Robotnik.
- Awesome Music:
- The boss theme for Knuckles
expands on his theme from the PC Sonic & Knuckles Collection/Sonic 3 prototype by adding inverted riffs from Stardust Speedway, not only making an already good theme even better but serving as effective foreshadowing for the story's big twist. - The beloved Sunset Park Act 3 returns in glorious Genesis form.
- Egg Zeppelin has a hectic and sinister tone reminiscent of Sky Base Zone.
- While Robotnik Winter Act 1 is a great improvement of the original theme because of the groove and references to Brad Buxer's Ice Cap, Act 2 has a bittersweet feeling to it which gives a perfect contrast between the fun you can have in the snow and its (supposedly) nuclear origins.
- Metal Sonic's 2nd boss theme is an exhilarating hybrid remix of Never Let It Go (the music for Death Egg's Eye) from Sonic the Fighters and both versions of Stardust Speedway Bad Future from Sonic the Hedgehog CD.
- Atomic Destroyer Act 2 sounds like a jam straight out of a 16-bit rave party, and encapsulates the danger of this endgame stretch.
- Final Trouble is a fast-paced, epic, original tune that is partially a Dark Reprise of Super Sonic's theme and also references Triple Trouble's title screen theme and credits themes, U.S. Stardust Speedway Bad Future and The Doomsday Zone.
- The boss theme for Knuckles
- Fridge Brilliance:
- In the Prequel comic, Knuckles is attacked by Metal Sonic in the final panel of his page. The final panel is him, Fang and Robotnik all stating they need the Chaos Emeralds. It seems like a rather sudden swerve... but it's not Knuckles saying that; It's Metal Sonic after capturing him and locking him up in Robotnik's fortress. In addition, it may also hint at the idea that he has his own ambitions that happen to coincide with Robotnik's to a certain point, as he's highlighted separately from Robotnik, as if he was a rogue agent like Fang and explaining why he didn't turn tail and leave with Robotnik.
- It makes sense that Dark Metal Sonic is powerful enough to harm Super Sonic with some of his attacks. The cutscene prior to Final Trouble Zone has Metal Sonic use the Dark Emerald to empower himself enough to easily knock Sonic and Tails unconscious before creating duplicates of the Chaos Emeralds, giving him 8 Dark Emeralds which he absorbs to become Dark Metal Sonic. With that in mind, it means that Dark Metal Sonic manages to surpass Mecha Sonic MK: II in terms of sheer power by actually being strong enough to make Super Sonic lose rings.
- Fridge Logic: An inconsistency inherited from the original and made more obvious by the seamless nature of zone transitions: the game goes from daytime in Great Turquoise to sunset in Sunset Park, to daytime again in Meta Junglira.
- Funny Moments:
- At the end of the Sunset Park Act 3 boss fight, the boss is damaged and a goal post appears to signal the level's end. Cue the victory theme for a moment before the train crashes, sending wreckage out onto the outskirts of Meta Junglira. The parts crash next to whoever you're playing as, with the head coming last... and, a second later, getting flattened by a conveniently-placed piece of rubble that tumbles on top of it really fast.
- At the end of the later two fights against Fang, the player character can get him buried under the ground while he's stuck there near-helplessly, exactly like in the original game.
- In Atomic Destroyer Act 1, Fang tries to fight Metal Sonic with his little gun, only to panic and flee when the robot dashes on him.
- After unlocking Knuckles, he'll sometimes pop up on the title screen briefly behind Sonic and Tails with a funny look on his face.
- Good Bad Bugs: It is possible to glide down the Egg Zeppelin as Knuckles and land on the cutscene trigger for Robotnik Winter Zone. In the final content update, this glitch is preserved and the zeppelin will not burn and crash in the background if you beat the level in that way.
- Magnificent Bastard: Metal Sonic FULL STOP. As seen in Knuckles' story, he attacked Knuckles before taking his appearance to trick Sonic and Tails into thinking Knuckles had been duped into fighting them once again. Antagonizing the duo through the game in his efforts to defeat them and gain their Chaos Emeralds, Metal Sonic develops a backup plan after one too many defeats, retreating before waiting for Sonic and Tails to defeat Dr. Eggman, before ambushing them while their guards are down while they have all seven Chaos Emeralds. He even goes so far as to stomp the two unconscious to beat the Emeralds out of them. Using the Chaos Emeralds' negative energy, Metal Sonic achieves a new transformation and nearly kills Sonic and Tails, who only lived thanks to Knuckles and even Fang the Sniper's timely intervention.
- Remade and Improved: While the original game is considered to be one of Sonic's best titles on the Game Gear, the remake is largely considered to be a massive step up from it, due to it being based off of the Genesis Sonic titles, allowing it to break free from the hardware limitations the original game had, providing greater and more elaborate level design, an expanded storyline, a revamped soundtrack, new zones, mini-bosses at the end of first acts, improved bosses for second acts, and an epic True Final Boss.
- Scrappy Mechanic: While the snowboard section of Robotnik Winter Act 2 is an exciting Sudden Gameplay Change, the sudden comeback to the usual sideview platforming level while remaining on the snowboard can make you lose some lives on your first playthrough, as you suddenly have to press the right button to avoid the avalanche.
- That One Level: Atomic Destroyer Act 2 is a marathon of a level with many claustrophobic corridors full of hazards, all culminating in an elevator sequence with shrinking platforms and a mid-boss to fight. Rings are also scarce throughout the Act, making matters worse.
- Underused Game Mechanic: All of the monitors from the original game that provided mobility enhancements beyond Power Sneakers are either changed to mandatory vehicle segments required to progress (Rocket Shoes, the Jet Board, and the Sea Fox) or axed entirely (Hyper Heli-Tails and the Propeller Shoes). The odd one out is the Spring Shoes, which is reduced to a singular appearance in a tiny section right at the end of a secret stage.
- Unexpected Character: Who could've guessed that Metal Sonic, in the game's true ending, would transform into a black Super version of "Rocket Metal" from Sonic the Fighters, and then the tall, red Metal Sonic concept drawn for the cancelled Sonic X-treme? In addition, an update released for the first anniversary of the full release added Amy Rose to the Free Play character lineup.
- Visual Effects of Awesome: Immediately when you enter the Eggrobo boss room in Atomic Destroyer Act 2, there's a pseudo-3D parallax effect in the background, the angle seamlessly changing as you pass it.
