Sonic the Hedgehog Megamix (also known as Sonic Megamix) is a ROM hack of the original Sonic the Hedgehog game by Team Megamix, led by Simon "Stealth" Thomley. It takes the original game and gives it an extreme overhaul, including new level layouts and graphics, new moves for Sonic that he gets in future games, and 4 more characters besides himself (Tails, Knuckles, Mighty and even Shadow), each of them having their own abilities and Super Modes, as well.
Sonic Megamix is among one of the longest-standing Game Mods for a Sega Genesis Sonic title in development, having been around since 2005, and still being upgraded further even with public versions of it already out to be played. It has become such an expansive hack that it was ported from a Genesis format to a Sega CD format, allowing it to run Redbook Audio music and even play on an actual Sega CD when properly burned to a CD-R.
The most stable version is 3.0, its final Genesis revision before moving onto to its first Sega CD revision in Version 4.0b, which is its most recent public version while also being classified as "unstable" due to not being finished. A leaked newer version that fans, and reluctantly, Team Megamix, call 5.0 or 5.0b, and can be downloaded on Team Megamix's site.
Stealth, himself, has released a trailer that contains even further updates to the game, and letting us know right in the trailer's title that the game is Never Cancelled. He has also posted a tech article on the current state of the game, and promised that if he gets enough donations through his Patreon page, he'll look into creating a stable version of Version 4.0b, which he dubs Sonic 1 Megamix as the game changed so much since then it was essentially no longer Sonic 1.
On the fateful day of 07/02/2016, however, Stealth declared Sonic Megamix as originally envisioned couldn't be worked on any more due to most of the original team having moved on to other matters. He still plans to eventually release what's been done of the project in a presentable fashion and the game's engine as open source.
Not too long after, it was revealed Stealth was involved in the development of the official Sonic Mania game. Much like back when Taxman's Retro Sonic Nexus fangame had to be cancelled in favor of the Sonic CD remake, fans were pretty much ok with how things turned out.
This game provides examples of:
- Art Evolution: Sunny Shores Zone, the modded version of Green Hill Zone, was originally called Sunset Hill Zone. Its entire design changed with its name, with the zone changing from a sunset-based Palette Swap of Green Hill to an even sunnier version of it with brand new graphics. Compare Sunset Hill◊ to Sunny Shores◊.
- Call-Forward: As this hack was made from Sonic 1, nearly everything Sonic can do here is based on something he would be able to do in a game released after Sonic 1 when the game's Control Scheme is set to "Megamix", including:
- Sonic the Hedgehog CD: The Super Peel-Out
- Sonic the Hedgehog 2: The Spin Dash and Super Sonic. Sonic's entire moveset is reduced to that of this game when his Control Scheme is set to "Classic", meaning the only move he has access to at all times is the Spin Dash.
- Sonic 3 & Knuckles: The game's speed and physics in general have been upgraded to remove all of the speed caps that every game before this one had.
- Sonic Adventure: The Homing Attack and Lightspeed Attack
- Sonic Adventure 2: The Light Dash
- Speaking of Super Sonic, he can also jump dash in any direction the player holds if he isn't near an enemy, just like Hyper Sonic in Sonic 3 & Knuckles, and with an S-Monitor, he can fly in a straight path for a limited time similar to how he could be used in the True Final Boss of that game. Hyper Transformations outright make a return in the leaked "5.0" version via a secret code, and any characters with S-Monitor-only abilities get to keep them for as long as their Hyper Transformation holds out.
- Demoted to Extra: Destroying a Badnik now releases a single Ring instead of an animal. The animals only make a token appearance at the end of each zone.
- Green Hill Zone: Sunny Shores Zone (formerly Sunset Hill Zone), which is actually the Trope Namer with a complete makeover.
- Elemental Powers: The elemental shields from Sonic 3 & Knuckles are featured in this game.
- Embedded Precursor: All of original zones from Sonic 1 were kept intact, and can even be played with the hack's new characters, controls, & physics.
- Flash Step: Shadow's unique ability for this game, which lets him jet off in a quick boost for 5 rings.
- Flight: One can control Tails' flight just like in Sonic 3 & Knuckles. Super Sonic can also achieve this after breaking open an S-monitor, but only for a limited time. If he becomes Hyper Sonic in the "5.0" revision, he can do this for as long as he stays in that form.
- Luckily, My Shield Will Protect Me: Mighty uses Sonic's moveset from Sonic 3 & Knuckles, right down to being able to use Sonic's Insta-Shield and his jump moves of that game's elemental shields. New to this game is Mighty's ability to store up to 4 shields and being able to switch between them on the fly to take advantage of the different immunities and attacks each of them have (the one exception being Sonic 1's, which has no additional abilities outside of Mighty's Super Mode).
- Palette Swap: The earlier builds of the game show that the new zones started out as palette swaps of the original Sonic 1 zones. As newer versions get released, more zones end up getting complete makeovers that go above and beyond this trope. See Art Evolution above for an example.
- Pinball Zone: Spring Yard Zone is upgraded to City Outskirts Zone, replacing the purplish evening colors of its background to bluish nighttime colors, as well as adding faster sections and loops-de-loops that Spring Yard noticeably lacked.
- Secret Character: Tails and Knuckles were originally intended to be unlockable characters. Note how the storyline as written on the website does not mention them.
- Shout-Out: Several. Because this hack is based on the first game, many moves, items, graphics and even music have appeared from later Sonic games and other games such as Columns 3 and Ristar. Even sound effects are ported from other games, such as the title screen confirm sound being Gunstar Heroes's own, the Large Ham Announcer from Street Fighter Alpha 3 calling the start and end of boss fights, and even tracks from Mega Man: The Wily Wars (particularly the Password theme and the famous Wily Stage 1 theme from Mega Man 2).
- Super Mode: All 5 characters have one, and can use it after getting 6 Chaos Emeralds instead of 7, since Sonic 1 only had 6 emeralds (though according to the story, Eggman brought the seventh one along with him). This game allows you to change back to normal in order to conserve rings. The leaked "5.0" revision brings back Hyper Transformations from Sonic 3 & Knuckles, Super Not-Drowning Skills and all, at the cost of a faster consumption of rings, and they can be access through every characters' Super Transformation after putting in a secret code.
- Title Drop: The word "Megamix" is used in the Control Scheme of the game's "Preferences" menu to refer to the new moves and techniques the playable characters can use.
- Under the Sea: Misty Maze Zone, the hack's update to Labyrinth Zone. It replaces Labyrinth's Underwater Ruins setting with an Atlantis-esque seascape from one of Sonic the Hedgehog CD's Special Stages.
- Unwinnable by Mistake: The most recent version (the tentative 5.0 version) cannot be completed by anyone except Tails (without cheats), as the layout for Starry Night Zone Act 3 is completely broken.