The Sonic Formula

Sonic the Hedgehog is a beloved franchise, known for the mix of high-speed platforming and quirky adventures. But how consistent is it and what has worked out?

Defining Sonic

For those under a rock, Sonic the Hedgehog is a video game series that debuted in 1991 and has since expanded to cartoons, comics, and movies. Developed by SEGA's Yuji Naka, Naoto Ohshima, and Hirokazu Yasuhara, Sonic was created to compete with Nintendo's Super Mario and replace SEGA's former mascot, Alex Kidd.

The protagonist is Sonic, a blue hedgehog "with attitude" who can run at the speed of sound. The games follow a simple premise: zooming through structurally absurd locations to foil the plans of Dr. Eggman (Ivo Robotnik), a mad scientist scheming to exploit the wildlife and ancient artifacts to build a robotic dystopia.

The series' reputation is widely known for been a roller-coaster. The game quality, and thus, fan reception, often hinges on SEGA's shifting priorities, resulting in some entries being praised while others are panned. The franchise’s appeal to teenagers and lax copyright enforcement have also spawned countless fanfics and fangames, which similarly range from beloved to infamous.

Defining Sonic's gameplay identity

Let's look no further than the 1991 game for Genesis. At its core, the game has several features that establish the series identity from there on:

Momentum-based movement

Sonic accelerates as he runs, up to a short cap. This means moving at maximum speed allows Sonic to jump farther, while combining slopes with charged spins lets Sonic reach otherwise inaccessible areas or shortcuts.

Risk vs. reward is central. The games encourage speed, but rushing reduces reaction time to appearing hazards. The games evaluate mastery by the ability to complete levels without slowing down by rewarding a time bonus, making the series natural speedrun material. Later stages introduce spikes, pistons and instant-death pits, which require both speed and precision.

Action-friendly level design

From the start, the world feels tailor-made for Sonic. The iconic Green Hill Zone features flat hilltops, slopes, upward ramps, springs, and floating platforms. The spacious level allows Sonic to test horizontal and vertical mobility. Many early stages follow a similar open-ended layout to encourage experimentation with physics, while later stages are more demanding on precision and reaction time.

Absurd engineering appears to follow Sonic everywhere. Even populated cities, ancient ruins, and Eggman's bases are filled with loops and gimmicks that serve no realistic purpose outside of making navigation feel engaging. Levels are often grouped into Zones (up to three per Zone) that follow the same aesthetic.

Sonic's character is someone who naturally loves running. Levels that confine Sonic to enclosed spaces or force waiting for timed mechanisms are notoriously poorly received.

Levels are accompanied by energizing soundtrack, a consistently praised element across the series. The visual and music ambiance are as crucial as the mechanics.

Rings

Rings act as main collectibles and are placed abundantly, often right on Sonic's path. They serve two roles:

1. Shielding: If Sonic is hit with at least one ring, he'll avoid losing a life, but some or all of his rings are scattered and disappear if not picked up shortly. This makes holding to a ring top priority, which is made challenging in later stages, where hazards are relentless and rings are scarce. This replaces a traditional health system with a risk-reward mechanic where mistakes can be recovered from, but consecutive errors force restarts.
2. Scoring: If the player keeps picking up rings along the way, they may be rewarded with 1-Ups from both the score and ring bonuses. Games without lives mechanic instead treat rings as in-game currency.

Items and score

Across levels, monitors are placed in hidden spots that grant power-ups, such as:

• 10 rings
• Temporary speed boost
• Bubble shields
• Extra lives (1-Up)
• Temporary invincibility

These reward exploration and an experienced player would know where to look to make progression smoother.

The points evaluate the player's performance, and a certain amount grants a 1-Up. A fast completion gives about as much as going out of the way to collect items or attacking enemies, so the player has to minmax their priorities. Aside of that, they mainly serve as a nod to arcade culture's scoring systems.

The games also feature Chaos Emeralds as secret collectibles that are granted upon completing hidden and challenging minigames. Collecting all emeralds rewards skilled players, typically with the good ending.

Path branching

Stages are linear at large, but split and converge in many places, providing multiple options to reach the end. Some levels are more open and allow jumping between paths, while some are divided into discrete obstacle courses. Some levels contain shortcuts with obscured connections between paths or hidden entrances. This adds replayability through experimentation, as some paths may prove to be more efficient.

This leads to another point, dangerous paths often yield greater rewards. Levels with high elevation or increased hazard presence contain bonus items and can even be faster than safe ground routes.

Later games with multiple playable characters also introduce character-exclusive paths. When Sonic's gimmick is momentum, other characters use areas Sonic can't with their abilities, creating gameplay variety.

Enemies and Bosses

Levels are filled to the brim with Eggman's robots. They are functionally nothing but hazards that can move and be destroyed. An enemy has a very simple method it can be defeated with, typically by being jumped on while avoiding an attack.

Players are encouraged to avoid combat since it's unnecessary, but sometimes enemies are just in the way. Doing so regardless grants the player some extra points which can contribute to bonus 1-Up.

Usually every third stage is dedicated to combat with Dr. Eggman. They normally follow the same principle, the machine will attack Sonic aggressively before briefly exposing its weak spot. This tests the player's agility and pattern recognition, as bosses are safe to approach only in a specific manner.

Cartoonish tone

Sonic's target audience are young teenagers. This means violence is limited to characters getting beaten up with no injuries. While the threat of death is explicit, it's not expected to actually happen.

While he's not an idiot, Dr. Eggman's ambitions and megalomania are hilariously over-the-top, and he can be foiled with no consequences. Other villains can substitute Eggman in areas where he wouldn't fit narratively. Meanwhile, heroes provide a lot of snark that emphasize their free-spirited nature.

The games avoid a complicated narrative and the stakes don't typically go beyond "The villain will rule the world if not stopped". Side-characters have own arcs, but they stay in the backseat. Since Sonic and Eggman are not a serious characters, they feel out of place in a serious story.

Evaluating every game

So with that in mind, let's see how games handle the design philosophy and how this contributes to critical reception.

Disclaimer, by every game I specifically mean every platformer that is known enough, sorry GameGear. Sonic also has a lot of spin-offs, but with different genres come different game designs. The following list is also an aggregate of various reviews along with what I remember.

While the mechanics come and go, it's commonly recognized by fans that the franchise had two major overhauls, some games mainly fall into specific groups of design philosophies.

Classic Sonic

Defined by being 2D and focus on landscape physics. The games are designed with continues and game overs in mind, so the difficulty can be unfair to new players since repeated playthroughs are expected. The plot is practically non-existent and characters don't talk, though there is a recurring theme of environmentalism. The artstyle reinforces a kid-friendly aesthetic.

Sonic the Hedgehog (1991)

Praise:

• Series-defining. As the first entry, most things discussed come from here, which to some extent all games still follow.
• Innovative for it's time, the "blast processing" (which was a marketing buzzword and not a specific technical capability) of the Genesis console allowed games to do more on screen compared to other consoles, with Sonic demonstrating it by going through levels with no pauses.
• The graphic design of the levels is still considered remarkable for 16bit style.
• Soundtrack is rendered from live performances, making it sound impressive and memorable despite technical limitations.

Criticism:

• Many hazards kill Sonic instantly regardless of rings, like spikes and pitfalls, causing many hard to avoid Game Overs..
• Marble Zone and Labyrinth Zone are hazard-packed mazes which restrict Sonic's movement. Mechanics that require waiting in place also kill both the momentum and player's patience.
• The Special Stage uses a gravity mechanic Sonic has little control over, making it very easy to fail and only a few opportunities to retry across the game.
• The final boss is tedious and has little room for error, while not looking impressive being just four pistons.
• Sonic's movement can feel sluggish compared to later games that introduce new mechanics.

Sonic the Hedgehog 2 (1992)

Praise:

• The level design is more refined following the previous game.
• Introduces Tails, setting up a precedent of various cartoon animals assisting Sonic against Eggman.
• Adds multiplayer modes for extra replayability.
• Gives Sonic new ability in Spin Dash, which expands the movement capability.
• Collecting Chaos Emeralds unlocks the Super Sonic power alongside the true ending, giving an incentive to complete Special Stages.
• Chemical Plant Zone and Casino Night Zone are filled with gimmicks that make it entertaining to even go through them.

Criticism:

• Tails's rubber-band AI can be a hindrance as he tends to run into hazards, which is detrimental in Special Stages, which additionally unfairly raise the victory condition as if expecting co-op that hasn't been implemented.
• Chemical Plant Zone Act 2 contains an underwater segment that is much more difficult than the rest of the level.
• Metropolis Zone and Wing Fortress Zone have some enemies with projectile attacks are out of Sonic's reach, alongside some jumps of faith that make it easy to miss platforms.
• Bosses in general have a small window of opportunity to hit the weak spot, resulting in players often getting hurt while attacking them.
• The final boss are two bosses in a row that have a lot of waiting time, don't provide rings, and are hard to dodge, forcing the player to rely on memorization instead of reaction.
• Despite the marketing focus, removing Sonic's speed limit has introduced glitches.

CD (1993)

Praise:

• Sega CD allows more detailed and animated backgrounds with more colors, turning levels into a visual spectacle. The soundtrack also takes advantage of the new hardware.
• The intro and ending cutscenes give the entry likable anime energy.
• Introduces Amy, which in turn expands Sonic's characterization.
• Time travel mechanic splits off already non-linear level design, with incentive to explore around.
• The duel against Metal Sonic is memorable for the fair amount of challenge and the narrative significance.

Criticism:

• Dark Future environments are depicted as too grim for the series. The nightmare-inducing boss theme in the US version also isn't helping.
• The levels have more verticality but have less straight paths, as well as levels being massive in size, making the game a lot slower.
• The time travel mechanic is unnecessarily cumbersome to execute depending on a location, as it requires running a certain distance with no interruptions.
• Getting the good ending turns exploration into a lot of work since the player has to search for the object to destroy across every level.
• The Special Stages are difficult to control, while 3D elements have deceptive perspective.
• The final boss is considered too easy.

3 & Knuckles (1994)

Praise:

• The combined game effectively gives more levels in one pack than a player can expect, as well as having four campaigns. Not many games can provide so much content, and the entry is widely considered the franchise's peak based on this.
• Tails now allows co-op with a second controller, letting two players to clear stages easier and reach secret areas.
• Knuckles goes through an understandable character arc in a game that otherwise lacks a narrative.
• The pixel art and level complexity is pushing the console's capabilities to the limit.
• Bosses in general are more gimmicky and engaging.
• The secret final boss provides a grandiose confrontation and conclusion to the plot.

Criticism:

• The two games separated show major signs of underdevelopment, which is why the combined version supersedes them.
• While Super Emeralds and Hyper powers provide more challenge and reward, many have considered them narratively and mechanically redundant.
• Carnival Night Zone Act 2 contains a unique obstacle that blocks progress and how to operate it is not described even in the manual, something the designer apologized for.

Knuckles' Chaotix

Praise:

• A whole adventure not about Sonic has intrigued fans.
• The mix of 2D and 3D provides a unique aesthetic.
• The final boss is very intimidating in its design.

Criticism:

• The chain ring very often hinders movement. AI-controlled characters are barely working.
• Extra lives being removed by allowing to restart levels significantly decreases the difficulty. Bosses in general also don't aim at the player and aren't difficult.
• Short development cycle resulted in heavy use of repetitive assets and other ways to cut corners.

3D Blast (aka 3D: Flickies' Island, 1996)

Praise:

• Both versions are known for programming ingenuity.
• Sega Saturn's 3D capabilities are impressive for its time, which are highlighted in Special Stages.
• Has received a Director's Cut later that fixes some issues, though some changes are divisive.

Criticism:

• Isometric camera clashes with visibility and directional controls.
• The game has large loading time between levels.
• Focus on collecting Flickies slows down the game.
• Special Stages in the Genesis version are considered bland-looking and pseudo-3D makes them more difficult.

4 (2010)

Praise:

• Was released at the time where faith in 3D games was at all-time low, so returning to the Classic formula was refreshing.
• Episode II introduces some original levels and addresses some problems with Episode I.

Criticism:

• Mixing Modern and Classic aesthetics feels awkward.
• Sonic's physics don't follow how it was originally and are difficult to control, while abilities show counter-intuitive behavior.
• Recycling levels from previous games feels uninspiring.
• The camera is too close, limiting the visibility of the obstacles.
• A lot of bugs and graphical errors are noticeable.

Mania (2017)

Praise:

• The return to popular roots, it's a brand new game that takes into account everything the Classic did right.
• Was outsourced to an indie studio that were already known in the fandom for releasing Sonic ports and being vocal fans themselves.
• Is done entirely in pixel art, which impressed players.
• A new villainous faction provides a sense of mystery without giving the plot too much focus.
• Multiple modes and playable characters extend replayability.
• The soundtrack is memorable.

Criticism:

• Half of the stages being recycled feels like nostalgia-pandering.
• The final level is tediously long.
• The initial release had noticeable glitches that were patched later. Some additions in Plus DLC have retroactively revealed that some features were initially unfinished.
• The time limit can cause Game Overs due to increased level length.
• The fire gimmick in Oil Ocean Zone Act 2 is a strain on the eyes.

Superstars (2023)

Praise:

• No recycled stages or gimmicks.
• Fans were intrigued by Fang's and Trip's characterization.
• Special Stages provide an engaging challenge.

Criticism:

• Despite the variety of new stages, they felt unoriginal, while the graphics look too simplistic.
• The levels aren't designed with co-op in mind despite the heavy marketing on it.
• Emerald Powers are considered too gimmicky and aren't even required to progress.
• Bosses are rather difficult in general, while the final boss is notoriously so.
• Lacks content for its price tag.
• The amount of glitches is rather high.

Dreamcast Sonic

The leap to 3D, which has its challenges in level design by sacrificing verticality in favor race-tracks levels. All characters are voice-acted and more thriller-like storytelling with worldbuilding is emphasized. The narrative implies the cast are residents of the human world instead of living on own planet. Eggman has a track record of being hijacked by more malevolent antagonists. Each entry is highly experimental and mixes up different playstyles.

Adventure (1998)

Praise:

• The new direction for Sonic was welcomed by fans.
• While the levels lack branching, the obstacles courses and track intersections still allow players to experiment.
• A plethora of new characters provide someone for everyone to root for. Voice acting introduce many character dynamics.
• Gamma's and Chaos's characterizations are compelling.

Criticism:

• Non-Sonic characters' gameplay is often considered inferior.
• The 3D camera is not well thought out.
• Big's campaign has frustrating gameplay and his characterization is polarizing.
• Polygonal graphics and exaggerated animations quickly got dated.
• The US release is full of glitches despite being delayed for a year and the DX release adds even more glitches.
• Hub-world sidequests unnecessarily stall progression.

Adventure 2 (2001)

Praise:

• 3D graphics are majorly improved.
• Shadow's story is both depressing and compelling, showing that Sonic can handle mature themes without going too dark.
• The missions are more streamlined with more polished level design.
• Players got too invested in Chao Garden.

Criticism:

• The camera still sometimes gets in the way.
• Multiple actions being tied to the same button has regularly caused wrong inputs.

Advance (2001; Advance 2, 2002; Advance 3, 2004)

Praise:

• Not considered a Classic game due to featuring Modern design and gimmicks, but still captures the 2D feel.
• Levels are complex and engaging.
• Cream's mother Vanilla has a memorable scene in the climax.
• Gemerl has depressing characterization and his relation to Emerl is a big mystery.

Criticism:

• The Gameboy's screen is too small and the hardware limitations decrease difficulty.
• Amy's gameplay differences make her frustrating to play with.

Heroes (2003)

Praise:

• Team dynamics allow them to contrast their personalities.
• Formations introduce an element of puzzle in progression, while some levels have actual puzzles that require exploration.
• Knuckles's characterization is considered an improvement from his previous appearances.
• Metal Sonic's role came out as a shock in spite of foreshadowing.
• The hub towns and human characters outside of Eggman are removed in favor of level select, which was welcomed by players tried of those.
• The story is greatly simplified to just chasing after Eggman while characters provide banter with each other within levels, making the plot easy to follow.
• Levels are visually impressive and have more branching.
• Big's role fixed his problems from previous games.

Criticism:

• Teams don't provide much variety outside of cutscenes and difficulty adjustments, it feels like playing the same game 4 times to get the ending.
• Chaotix missions that require collecting a certain amount of items are loathed due to these being easy to miss, requiring to redo stages over and over.
• Shadow's revival after his sacrifice in the previous game is considered a cop-out to capitalize on his popularity, and also isn't focused on despite being a critical plot point.
• How Special Stages work is not properly explained and the speed is inconsistent.
• Amy's obsession with Sonic feels extra obnoxious.
• Focus on fighting enemies with health bars alienated players who expected to traverse levels without interruptions.
• The rails mechanic often causes the player to miss and fall into pits due to wonky snapping.

Shadow the Hedgehog (2005)

Praise:

• Shadow's backstory is rich in storytelling and his trauma can lead him into different endings.
• Some players have appreciated tonal and mechanical differences from Sonic games.

Criticism:

• Shadow's aggression and use of guns is considered out of place in the Sonic series, while his lines are too childish for his supposed mature role, revealed to be caused by censorship close to the release.
• The game has 10 main endings, and players have no reason to go through them after getting the true ending. The game also oddly counts every combination of how the players have progressed as separate endings with minor optional dialogues, making it practically impossible to get them all 326 of them.
• The involvement of aliens in Shadow's backstory feels unexpected.
• The support characters outside of Sonic don't do much for Shadow aside of reminding him of his connections, players have expected more.
• The bosses have too much health while not being too difficult.
• Commander Tower blaming Shadow for Maria's death when he's working for the organization responsible stops any potential sympathy for him. His actual reason is only explained in another game.

Rush (2005; Rush Adventure, 2007)

Praise:

• Feels very fast for DS.
• Introduces Blaze, who is beloved as an example of strong female character writing and for being a rival to Sonic.
• Dual screen compensates for otherwise low visibility.

Criticism:

• Jumping is heavy for a 2D game.
• Adds a Boost mechanic that due to limited space slams you into a wall and sets a bad omen for future games.
• Dialogue can feel like it's taking too long.
• Bosses don't show enough hit opportunities.
• Amy's and Cream's portrayals are unnecessarily hostile.
• Captain Whisker working for Eggman is too obvious for a plot twist.
• Upgrading the ship in Rush Adventure requires farming materials by completing stages repeatedly for no reason. The ship itself also involves small minigames that only waste time.

'06 (2006)

Praise:

• The pre-rendered cutscenes look phenomenal.
• Level design has an impressive amount of detail.
• Shadow's characterization tones down his edginess from previous titles and makes him too competent compared to the rest of the cast.
• Mephiles shows a surprising degree of long-term planning and masterminding the plot behind the scenes, and ending up temporarily victorious.
• All playable characters are given an equal amount of focus in gameplay without altering playstyles by much.

Criticism:

• The game was infamously published with a lot of critical bugs, loading times, unfinished animations, and performance issues, from which SEGA took a massive hit and treated by the company with shame and self-deprecation.
• Princess Elise's role is limited to being kidnapped and rescued by Sonic repeatedly, relying on an already loathed damsel stereotype. Her romantic subtext with Sonic despite barely knowing him is also unnecessary in the presence of Amy, uncomfortable, and devalues her role in the lore.
• Consequently, Sonic's own role is reduced to being Elise's support and doesn't feel like the protagonist. Sonic doesn't even learn who the villain is until too late.
• The time travel plot is hard to piece together.
• The story ending with a timeline fix feels like it undermines the achievements of the characters by having them lose all memories.
• Eggman's redesign is disliked for being too realistic.
• Silver is generally disliked for his hostility and for being easily manipulated.
• Blaze's appearance in Silver's future is yet to receive an explanation and writers admit the continuity error.

Rivals (2006; Rivals 2, 2007)

Praise:

• The levels are 3D while constrained to 2D layout, providing it with the feel of Classic gameplay while offering visual spectacle as areas twist and turn.
• The graphics look great for a handheld console.
• The sequel provides over a double of content.

Criticism:

• The characters clashing against each other instead of combining efforts against Eggman Nega feels like a cop-out excuse to make them race.
• Rubber-band AI snapping the opponent to the player if they are too far is considered unfair.
• The campaigns are identical outside of the reason they've ended up being involved in the plot, expecting the player to go through multiple playthroughs.
• The games have tons to collectible card achievements that can take forever, while some are nearly impossible to get.

Storybook (Secret Rings, 2007; Black Knight 2009)

Praise:

• Sonic being the sole protagonist in Secret Rings address the ongoing issue of characters bloat.
• The Arabian Nights and Arthurian Legend worlds allowed fans to come up with other potential crossovers.
• Sonic has received some cynical characterization, which is considered understandable to match the villains' ruthlessness and heavy subjects. Instead of feeling out of place, it makes him sound profound and experienced.

Criticism:

• The motion controls make the games barely playable.
• Focus on combat reduces levels to straight paths.
• Sonic with a sword feels awkward when he never used one before.
• The messages can come off as a bit nihilistic.

Boost Sonic

Can be considered as damage control after Shadow and '06. The gameplay is simplified to lane levels that emphasize going as fast as possible, where going up or left switches sides on a track, and the path variety is minimalized. Exploration is rarely as levels play almost like autoscrollers. The replay value is compensated by going for the high score and optional challenges. The narrative panders to younger audience. Some elements are inserted for the sake of nostalgia.

Unleashed (2008)

Praise:

• The 3D has been greatly improved to look high-quality even outside of cutscenes.
• The daylight sections make blasting through stages entertaining.
• The Werehog stages are considered well-made individually, they just clash with traditional stages by being in the same game.
• Amy's characterization was dialed back to having interests other than Sonic.

Criticism:

• The Werehog both conceptually and for switching the game to a Beat em Up is considered too odd for the series, while doesn't provide sufficient narrative reason and slows down progress.
• New engine and overambitious with particle effects have caused framerate issues.
• Platforming in Eggmanland level is too demanding and takes absurdly long time.
• Sonic's increased speed becomes a downside as obstacles are hard to respond to, even before the upgrades make him even faster.
• Tails's cowardly characterization wasn't welcomed by fans, while some find Chip an annoying gimmick sidekick.
• Eggman is made too comedic to the point of not feeling like a threat.
• Collecting medals to unlock next levels kills pacing.
• Quick Time Events clash with Sonic's style.

Colors (2010)

Praise:

• Sonic has increased his snarkiness and returned to his "cool" characterization after several games depicting him as flawlessly heroic.
• After being chronically back-stabbed by other villains, Eggman remains as the sole threat, with a dangerously sociopathic personality.
• The levels are less linear compared to the previous game and feel like a return to Dreamcast design.
• Overall is considered to be SEGA trying to avoid risks by keeping things simple and focusing on the best elements of 3D games.

Criticism:

• The Wisps feel too gimmicky.
• The overall lighthearted tone and comedy feel too childish.
• The major differences between portable and console version have divided fans into two camps.
• The Ultimate re-release has failed to mention intentionally being released in a beta state to collect bug reports, which the reviewers didn't account for. And even after the proper release some crucial bugs and crashes weren't fixed.

Generations (2011), Shadow Generations (2024)

Praise:

• Is considered a proper celebration of the franchise's anniversary by combining several Sonic playstyles and being respectful to continuity.
• The recycled levels and bosses have received improvements since their original appearance.
• Silver's new boss fight has retroactively improved his perception.
• Shadow's expansion and side-material make a heartwarming conclusion to his previously divisive character arc. Black Doom returning as the main villain has improved his reception alongside addressing some plot holes from 2006 game, while new levels took hints from years since the 2011 release.

Criticism:

• Despite ambitious stakes, the plot is practically non-existent and Eggman lacks screentime.
• Despite their importance in Sonic's life, all of Sonic's friends are reduced to hostages and play not role in the story.
• The neverending tips from side-characters during the final boss quickly gets annoying.
• Since the challenges are fairly easy, the game can be completed shortly and lacks replay value.
• Despite the premise allowing it, no downloadable content has disappointed fans, leading to mods adding new nostalgia levels.

Boom (Rise of Lyric, 2014; Shattered Crystal, 2014; Fire & Ice, 2016)

Praise:

• Fans generally were forgiving for the game trying to go with an original story and action-adventure style.
• The accompanied cartoon series amplifies comedy, snark and meta commentary, giving interest to the subseries while the games themselves were panned.
• Fire & Ice is considered doing the best for the formula, even if too late.

Criticism:

• New redesigns are too humanoid and unfamiliar, while trying to restart the continuity alienated old fans.
• Lyric feels too generic for a villain, while his alleged bigger threat compared to Eggman ended up being unwarranted.
• Some bugs break level progression and the amount is compared to 06 in severity.
• Despite restarting the story, the backstories of the heroes are not elaborated, the cast already know each other when the plot begins and their motivations are barely mentioned. Other characters also have a lot of tell don't show when it comes to their new characterizations. A lot of new plot points were left hanging.
• Shadow's limited screentime amounts to being a straight villain without an explanation. Metal Sonic similarly gets no personality, his old design has raised questions, and was accused of being included for nostalgia.

Lost World (2015)

Praise:

• Amy, Tails and Eggman showcase improved character writing. Eggman in particular shows a surprising amount of patience while working together with his nemesis.
• The tone mixes up lighthearted writing with unsettling threats.
• A different gameplay style provides unique challenge.
• The fandom has showed increased interest in Zeena's humanoid design.

Criticism:

• The gameplay is commonly accused of being a rip-off of Mario Galaxy.
• Boost being replaced with parkour gimmicks is fixing something that wasn't broken and makes levels feel slow.
• The Deadly Six are hard to take seriously.
• The patch retroactively has revealed the game was originally released with more glitches than what was reported.

Forces (2017)

Praise:

• This shows Eggman's empire at its scariest, with the destruction of the environment being commented on by the displaced population instead of being implied.
• Infinite is genuinely creepy if one to look past his motivations.
• The connection to Sonic Mania felt like an attempt of introducing deeper continuity between games.
• For some, playing as an original character let them feel a personal connection to Sonic as was intended. His arsenal also provides gameplay variety.

Criticism:

• Eggman's early victory is disproportionately dark compared to how short-lived it was, not helped by his moments of cruelty being cut out from the final release despite leaving references to them, and characters still not treating the war seriously.
• The levels are considered too short and too straightforward even on Hard difficulty.
• Infinite's characterization is considered too edgy even compared to Shadow, and his backstory is met with mockery.
• Returning villains turned out to be Infinite's illusions, which offended long-term fans.
• Customizable player character is accused of pandering to the wrong side of the fanbase.
• Tails's portrayal makes him too cowardly compared to his previous appearances.
• Reusing nostalgia levels despite not being an anniversary title is uninspiring and feels like imitating Generations. The bosses similarly feel unoriginal even if new.
• The role of dimension-traveling Classic Sonic is to excuse 2D stages, not being own character.
• Despite being one of the strongest fighters, Knuckles is pushed into the exposition role and his leadership skills are questionable.
• SEGA has thought using an adult restaurant for promotion is a good idea, it was not.
• Chaos Emeralds aren't present, while Super Sonic was turned into a paid DLC.

Frontiers (2022)

Praise:

• Open-world level design is novel and refreshing.
• Sage was greatly welcomed, while her relationship with Eggman sparked speculation.
• Sonic's moveset on ground is greatly expanded.
• The use of rock songs as boss themes made these encounters especially memorable.
• The melancholic characterization of Amy, Tails and Knuckles provided unexpected personal depth, as well as referencing their arcs in previous games. Meanwhile, Sonic is emphatic to everyone's problems despite being on a constant threat of dying himself.
• The main villain has shown shocking degree of manipulation while being disproportionately threatening lore-wise.
• Developer notes reveal that the franchise would have been killed off if the game didn't sell well.
• Final Horizon DLC has fixed some issues regarding the ending.

Criticism:

• The launch featured rendering issues that took a while to patch.
• Bosses rely on button-mashing instead of agility and get repetitive.
• The overworld puzzles start repeating themselves.
• The final boss being a simplistic Shoot Em Up is jarringly out of place and shows that the proper fight wasn't finished in time.
• Cyberspace feel like an excuse to insert nostalgia levels people didn't care about in the first place.
• Final Horizon retooled the difficulty of overworld challenges, but now expects full mastery of new physics, to the point where many players were unable to even finish it. Further patches added more mercy.

Conclusion

From the above, we can summarize what the fanbase wants from the franchise.

1. Fans treat the gameplay loop of the first game as the high bar, which is polished further in direct sequels. Even 3D games follow similar design. The mechanics should allow player experimentation. The gimmicks are a hit or miss, while deviation from the norm often doesn't fit well with other mechanics and causes backlash, so any additions should be excessively playtested.
2. Players want control freedom and the ability to blast through levels. The ideal idle time for Sonic is zero and forced waiting is inexcusable. The levels should compensate between casual and hardcore players by providing alternate paths that require different degrees of mastery, not being linear obstacle courses.
3. Going through stages is as much of a challenge as it is a visual spectacle. A good game design would make segments with less hazards richly decorated to provide a unique experience. The soundtrack rarely receives a bad word, but it's still a reminder that music should fit the level theme.
4. People like a good story and Sonic can be surprisingly mature, but the writing should handle entertainment and thematic conflicts equally. Sonic is a cartoon animal fighting for freedom of others, not a horror survivalist who needs personal growth. If the tone is depressing, then it should be treated respectfully in entirety.
5. Dr. Eggman works best when he's both goofy and competent. Most of the humor comes from everyone insulting his overblown ego, but it should not decrease his competence, while devastating consequences of his potential victory should be a solid motivation to go against him.
6. Inclusion of characters outside of the two should serve both the gameplay and the narrative purpose. If a Sonic's ally doesn't have much to do then they shouldn't be included. The characters should also be own people with own issues, not riding on Sonic's presence.
7. People generally don't care about humans outside of Dr. Eggman's family as they clash with toon animals.

Is SEGA learning?

While SEGA is the usual target of criticism, one has to remember that they are a multi-national conglomerate with many businesses, while Sonic is handled mainly by the Sonic Team studio. For the sake of it being easy to follow I'll be conflating the responsibility to SEGA anyway.

SEGA has a consistent issue from the very beginning of prioritizing scheduled releases. Often at expense of quality control. Practically every game is known for leaving in bugs that affect gameplay, and it's unlikely they're going to manage that part better without some radical policy changes.

It appears that some kind of market research is done, but is repeatedly missing the point. If a game sells well, the company will think they did everything right and start working on a new game. If a game was panned, the company will assume people no longer want Sonic, instead of addressing specific avoidable issues. Despite the reviews making it clear what was disliked, some elements keep persisting, though later games attempt to avoid elements that have already caused controversy.

SEGA shows persistence in trying to make every game unique, even if the feedback is being vocal they rarely appreciate changes to the gameplay or characters, as it breaks Sonic's identity. It may possibly be caused by attempting to gain interest of new audience instead of relying on existing fanbase, but often it's the latter who keep the franchise going. Very notably, when the developer is someone who isn't Sonic Team, the gameplay is more conservative with increased playtesting, which reflects on higher ratings, showing that perhaps the outsiders usually have a better vision for Sonic than his own creators.

One thing to keep in mind is that SEGA has shifted more into arcade business. While Sonic is the main part of SEGA's branding, he pales in comparison to profits from pachinko machines, so the company doesn't have a lot of reasons to invest in the franchise aside from keeping it barely afloat. The relative lack of copyright control compared to Nintendo is also a tactic to keep Sonic always relevant in public's mind even when SEGA isn't doing much for him, allowing them to sit back then to step in when the demand increases.

It can be argued that Mania and Frontiers being commercially successful has piqued SEGA's interest, as they've started to pressure for more games being made more regularly while expanding to media outside of games. The releases of Superstars and Shadow Generations demonstrate more consistent quality. It can probably be said that the franchise has been on a more stable ground compared to a decade ago, as Sonic Team has finally pieced together than more oversight means more profit, but SEGA's head-in-sand management is still noticeable.

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