Developer: Sonic Team

Publisher: Sega

Platforms: Sega Saturn, Windows, iOS, Android

Predecessor: Sonic the Hedgehog 3 & Knuckles

Release Dates: US: September 9th, 1995 | Europe: September 21st, 1995 | Japan: October 3rd, 1995 | Windows: August 12th, 1998 | Mobile: October 24th, 2015

No. of players: 1-2 Players (Story Mode, Special Stage Marathon), 1 Player (Time Attack), 2-4 Players (Competition Mode)

Playable Characters

Sonic the Hedgehog

Miles "Tails" Prower

Knuckles the Echidna

Amy Rose (Rosy the Rascal)

Non-Playable Characters

Dr Ivo Robotnik (Dr Eggman) 

Metal Sonic MkII

The game would take place on Dreamyst Island, an island situated in the East relative to the other classic Sonic islands, the island is known for it's surreal environements (hence the name "Dreamyst") and beautiful views, powered by The Mythical Diamond (yes, that's its name). After his evil attempts failed on the other 4 locations (1, 2, CD and 3K), The new island has caught the interest of Dr Ivo Robotnik who was coveniently building his next invention, Metal Sonic Mk II, an upgraded version of his darling robot that surely won't fail him this time, he knew that this diamond is gonna be his best chance yet to finally defeat Sonic and his friends once and for all.

Eggman attempts to take The Mythical Diamond but this is when Sonic & co. arrive, they attempt to take it from him but they accidently shatter the emerald into pieces while doing so, and life, along with the Island's magic, began to fade away, so it's up to Sonic, Tails, Knuckles and Amy to retreve all of the shards before Eggman does and save the island!

The gang discovers in the good ending of the game that the Chaos Emeralds have the ability to boost The Mythical Diamond's effect even further, making the island the livliest it has ever been!

Visuals

The game would look amazing, each environement is super vibrant and colourful, you could tell it would be made by the same people who would go on to make Nights into Dreams and Sonic Adventure, the sprites would also be very detailed, yet still beautiful, and everything, wether it's a character or an object or a stage, would be very smoothly animated, almost comparable to Sonic Mania actually.

The game would utilize the capabilities of the Sega Saturn to bring some interesting visual effects, including 3D models, scailing/rotating and smooth colour transitions

There would also be animated cutscenes, they would commision Toei Animation again to do them, so because of that they would be similar to the ones seen in Sonic CD, there would be an intro, 2 endings, and some in the events themselves

Music & Sound

The music would be kind of similar to the Sonic Adventure soundtrack with some hints of Sonic CD here and there, it would sound amazing for the most part

This game would also feature extensive yet balanced use of voice-lines, mostly from the playable characters, Eggman and Metal Sonic MkII, nothing big, just short phrases and noises

The sound effects would be the same iconic sounds from the Mega Drive/Genesis titles, but now in CD quality, some of them would be re-used in Sonic Jam and the Saturn version of Sonic 3D Blast

Menu & HUD

The overall UI of this game would be fairly simplistic, the title screen would be your typical "sonic poses on an emblem" fair, but now, yet again, colourful and much better animated, once you press start at the title screen you would get a Sonic CD-esque "menu", you can select between "Main Game" which is, you guessed it, "Competition Mode" which is, again, you guessed it, "Extra Modes" which contains Time Attack, Special Stage Marathon and the DA Garden, "Options" which contains basic options for Sound and Gameplay, and "Level Select" if you inputted the level select code, once selecting main game you would see a "Select a Save File" screen very similar to the ones seen in Sonic 3&K and Knuckles' Chaotix, this screen would contain 8 slots, with options to delete a save using the X button, or copy a save using the Y button, the game by defaut uses auto saving but you can switch to manual saving by pressing the Z button, a character is tied to each save, like Sonic 3&K 

The HUD would also be nothing spectacular, your typical "SCORE", "TIME" and "RINGS" format as well as a life icon at the bottom, though now there would be an actual pause menu, it's very simple though, the options are "Back", "Try Again" (greyed out in the Special Stages for obvious reasons) and "Leave"

Story Mode

The gameplay is about what you expect for a classic Sonic game, you would play as one of the playable characters, each having their own movesets, and find hidden special rings (S3k Style) to go to the Special Stages to get the 7 Chaos Emeralds, there would be both mini-bosses and major bosses for acts 1 and 2 respectively and when you defeat a mini-boss (before Sacred Shrine Zone) you get one of the Diamond Shards back

Zones

There would be a total of 12 zones in the game (13 if we're counting the Super Sonic level), and as you can see, every level's name would be an acronym

Windy Wonderland Zone

Slippery Steps Zone

Soaked Scentuary Zone

Western Whiteout Zone

Decayed Debris Zone

Arrogant Ash Zone

Sacred Shrine Zone

Celestial Chase Zone

Jolty Joyride Zone

Cosmopolis Zone

Luminous Labortory Zone

Ethreal Egg Zone

Hazardous Havoc Zone

Special Stages

Unlike the main game, the special stages would be entirely rendered in 3D, it features your character running around a checkerboarded road chasing the chaos emerald, in these stages there are ramps and stuff like that, use the physics to your advantage and catch the chaos emeralds before your time runs out (your rings act as your timer)!

Extra Modes

Competition Mode

2 Players (or up to 4 Players using the Multi-Player Adaptor/Multi Terminal 6) can compete head to head in a multiplayer racing mode, players can race across 6 levels based on some of the main zones in the game, the player who beats the level first wins

if all of the other players finish the level then the last player will get a time limit, if they don't finish before hitting the time limit they will automatically lose, like Sonic 2's 2P mode.

Time Attack Mode

Very self explainatory, the player tries to beat every stage (except for Celestial Chase and Sacred Shrine for obvious reasons) as fast as possible and set a personal best. every level is unlocked periodically as you progress through the main story

Special Stage Marathon

Go through every special stage in order, lose once and you're out, try to get all of the Chaos Emeralds!

DA Garden Mode

The DA garden mode would return from Sonic CD, standing for "Digital Audio Garden", it's basically a fancy looking sound test though now it would come bundled with Visual Mode, also returning from Sonic CD, and it's basically a video player for the FMV animated cutscenes, both can be unlocked by beating the game with all Chaos Emeralds

The game would see a healthy amount of re-releases and remasters

Project Sonic Re-release

In early 1997, the game would be re-released for a lower price under the Project Sonic lineup of titles, this version actually features some bugfixes and refinements, and it would be often reffered to as "Rev01" or "Revision 1"

Sonic Jam + Sonic the Hedgehog 4 Console Bundle

In early 1998, a console bundle containing the Saturn as well as both Sonic Jam and Sonic the Hedgehog 4 in one disc would be released, this bundle is kind of like Nintendo's Super Mario All-Stars + Super Mario World bundle where Sonic 4 was actually integrated into Jam's Game Selection screen

Sega PC Windows Port

In late 1998, a port for Windows 95 and Windows 98 systems would be released under the Sega PC brand, this version was identical to the Sega Saturn version though the sound is in lower quality and the characters in the special stages use 2D sprites rather than 3D models

That version would be re-released multiple times across multiple publishers across multiple countries, with the most recent being in 2004

Mobile Remaster

In Late 2015, the game would get a remaster exclusively on mobile devices, featuring enhancements like widescreen support and extra content

In Mid 2018, the remaster would be relaunched under the Sega Forever brand, making it free to play but also adding ads, though users can pay a small fee to remove them

In 2026, the mobile port would be delisted from the app stores

Sonic Origins

The mobile remaster would make its first appearence on PC and consoles through Sonic Origins, where it was included as the 5th game in the collection, it gets the same changes as the other games like replacing lives with coins and adding extra modes (Boss Rush and Mirror Mode), the game is also playable in the Story Mode taking place after Sonic 3 & Knuckles, and the game would also get its own intro and ending animations even though the original version had animations already

Others

Other re-releases include: a port in Sonic Gems Collection that's based on the PC version (it still retains the limitations), and a re-release on Playstation Network, Xbox Live Arcade and Steam back in 2011, with the last getting delisted shortly before Sonic Origins' release along with the other games

• Sonic's Double Jump ability would go on to be reused in 1996's Sonic Blast/G Sonic for the Sega Game Gear, and a different looking Double Jump ability would become the standard for Modern Sonic games ever since Sonic Colours

• Amy's entire moveset would later be reused for the other games in the Sonic Origins Plus expansion as well as a slightly different version in Sonic Superstars

• Sonic 4 would be the third mainline Sonic game to be released in US and Europe before Japan

• Even though you would get a basic level select after beating the game, you could access a more advanced one much earlier by pressing up, down, down, down, up, up, and a+start in the title screen, and it would look similar to S3K's level select

• by inputting 19, 64, 02, 26 (Naoto Ohshima's birthday) in any of the two sound tests, debug mode would be activated