SegaGenesisRecomp gets first playable title: Sonic the Hedgehog

Gamemaster1379 · May 2, 2026

Sonic the Hedgehog has seen no shortage of PC ports over the years, official and otherwise, but this one is interesting for a very different reason. SegaGenesisRecomp is an early Sega Genesis / Mega Drive 68000 static recompiler, and Sonic the Hedgehog is currently serving as its first major proof of concept.

The companion SonicTheHedgehogRecomp project takes code generated from a Sonic 1 ROM and runs it natively on Windows, with Green Hill Zone now playable from start to finish, including all three acts and the boss fight. It is still early days, though: later zones are untested, some behavior is still being discovered and fixed, and this is not meant to be treated as a polished “definitive” Sonic PC port just yet, but as a jumping off port for Sega Genesis games getting their own static recompiler.

Still, as a technical milestone, it is a fascinating step. Rather than simply emulating the game or building another source port, the project is demonstrating that native recompilation of Genesis 68K game code can work in practice. If the approach continues to mature, it could open the door to more native ports, debugging tools, enhancements, and preservation work for Genesis games.

Sources:
SegaGenesisRecomp
SonicTheHedgehogRecomp

Renos44 · May 3, 2026

How cool Though given how Sonic 1 has already been completely reverse engineered and has tons of unofficial and official ports I personally wouldn't have picked it as a game to show off.

But i wonder if this opens the door to recompiling other famous 68000 stuff.

Jayro · May 3, 2026

I didn't know Sonic 1 was decompiled. I'd love it if Sonic Chaos got recompiled so we could get rid of and fix the slowdown.

tech3475 · May 3, 2026

Jayro said:
I didn't know Sonic 1 was decompiled. I'd love it if Sonic Chaos got recompiled so we could get rid of and fix the slowdown.

Though I haven't found a complete disassembly for Chaos, here's some other games which have been:
https://info.sonicretro.org/Disassemblies
https://segaretro.org/List_of_disassemblies

Jayro · May 3, 2026

tech3475 said:
Though I haven't found a complete disassembly for Chaos, here's some other games which have been:
https://info.sonicretro.org/Disassemblies
https://segaretro.org/List_of_disassemblies

I'm honestly surprised nobody has made a Sonic Chaos romhack for the Megadrive/Genesis that runs on real hardware.

Renos44 · May 3, 2026

Jayro said:
I'm honestly surprised nobody has made a Sonic Chaos romhack for the Megadrive/Genesis that runs on real hardware.

Technically Sonic chaos already runs on a Genesis since it is a master system game.

To add on the list fans have decompiled
sonic mania https://github.com/RSDKModding/Sonic-Mania-Decompilation
Sonic CD 2011 https://github.com/RSDKModding/RSDKv3-Decompilation
Sonic 1 and 2 2013 https://github.com/RSDKModding/RSDKv4-Decompilation
A work in progress for Sonic advance 1 and 2 https://github.com/SAT-R/sa2
Sonic Runners https://github.com/itsmattkc/RunnersDecomp
Someone just recently decompiled the PC version of Sonic R
Theres been talks of decompiling the adventure games but i don't think any real progress has been made

A port of triple trouble to the master system https://info.sonicretro.org/Sonic_Triple_Trouble_SMS

Reploid · May 3, 2026

Wasn't it recompiled before like 4 times?

Jayro · May 3, 2026

I wish more stuff would get ported TO the Sega Saturn... As a MiSTer owner, it makes me sad that it's a difficult system to develop on.

Gamemaster1379 · May 3, 2026

Renos44 said:
How cool Though given how Sonic 1 has already been completely reverse engineered and has tons of unofficial and official ports I personally wouldn't have picked it as a game to show off.

But i wonder if this opens the door to recompiling other famous 68000 stuff.

The primary reason Sonic 1 was the game of choice wasn't due to notoriety, but the fact it has a full disassembly already available. It was one of the easier choices to ground validation on a Sega Genesis Recompiler. It'll make games 2+ easier.

The real takeaway here is another Sonic the Hedgehog decomp/port, it's a matter of it being built in tandem with a Sega Genesis Recompiler, which will allow itself a headstart to other games on the system. Think n64recomp as an example.

I took a similar approach with nesrecomp. I started with a few games with known disassembly (Super Mario Bros, Faxanadu, Legend of Zelda, Megaman 3). Each of those helped validate behavior on the recompiler and improve it. Eventually I was able to start teetering on games that lacked explicit disassembly (Duck Hunt, Gumshoe, Dr Mario, Yoshi, Yoshi's Cookie), etc. As I added more and more games, the process for later ones was sped up. That's my aspiration for here as well.

Post automatically merged: May 3, 2026

Reploid said:
Wasn't it recompiled before like 4 times?

My understand is there's a number of decomps and recomps of various versions (including PC variants, etc). The primary value proposition here is the SegaGenesisRecompiler, and this is the tech demo. Can see my post above for more info on it.

Post automatically merged: May 3, 2026

Jayro said:
I wish more stuff would get ported TO the Sega Saturn... As a MiSTer owner, it makes me sad that it's a difficult system to develop on.

I'm currently focused heavily on an snesrecomp improvements to n64recomp. I am considering doing some other systems like recompilers from the Saturn if I can land thes projects I'm on now. If I can get something nailed down, being able to port from it may also open doors to port to it.

MeowthBlep · May 4, 2026

unfortunate that they used ai graphics

Robert Newbie · May 4, 2026

Man, Recomp is happening for more consoles. I'm looking forward to seeing how things progress from here.

I know there are some SNES games that experience slowdown, but are there any Genesis games that have similar performance issues? My real question is: Which games would benefit the most from static recompilation?

Gamemaster1379 · May 5, 2026

Robert Newbie said:
Man, Recomp is happening for more consoles. I'm looking forward to seeing how things progress from here.

I know there are some SNES games that experience slowdown, but are there any Genesis games that have similar performance issues? My real question is: Which games would benefit the most from static recompilation?

I'm not as familiar with Genesis's broader library, but I believe there are a few. I want to say Rocket Knight Adventures does in places. I think some tougher parts of the Sonic games may be here or there.

My primary ambition is that this opens up extensibility and porting to other platforms. Widescreen, mods. Etc.

As for SNES, I'm tinkering in that space too. Unfortunately, given the architecture of the SNES's 65816, building a recompiler for it is nightmarish.

Robert Newbie · May 5, 2026

Gamemaster1379 said:
I'm not as familiar with Genesis's broader library, but I believe there are a few. I want to say Rocket Knight Adventures does in places. I think some tougher parts of the Sonic games may be here or there.

My primary ambition is that this opens up extensibility and porting to other platforms. Widescreen, mods. Etc.

As for SNES, I'm tinkering in that space too. Unfortunately, given the architecture of the SNES's 65816, building a recompiler for it is nightmarish.

Yeah, that makes sense. I know that there are a ton of FastROM hacks for several SNES games, but I'm sure recompilation would be another way to really optimize a game. I've always imagined a day where Star Fox runs at a solid, high framerate and plays flawlessly (no input lag).

I'm really interested in the decompilation and Recomp spaces at the moment. I like developments that really invigorate the fanbase to try new things and implement improvements. The N64 and PS1 have my attention because PC ports would greatly improve many of the 3D games of that era.

SteinsGoat · May 5, 2026

Wow - that’s insane! Gain Ground definitive edition when?

Gamemaster1379 · May 5, 2026

Robert Newbie said:
Yeah, that makes sense. I know that there are a ton of FastROM hacks for several SNES games, but I'm sure recompilation would be another way to really optimize a game. I've always imagined a day where Star Fox runs at a solid, high framerate and plays flawlessly (no input lag).

I'm really interested in the decompilation and Recomp spaces at the moment. I like developments that really invigorate the fanbase to try new things and implement improvements. The N64 and PS1 have my attention because PC ports would greatly improve many of the 3D games of that era.

For sure. The spaces also interest me and I'm trying to see how I can help move the needle along. I did a tech demo for psx that had Tomba going, but I wasn't happy with the foundation, so I'm trying again but starting from the BIOS this time. Have memory cards and all that loading, but trying to get the rest of the interfaces working (copying, etc). Then will try to see if I can't get a game to MVP status under it.

cearp · May 5, 2026

Cool, stuff like this is always welcome!

MeowthBlep said:
unfortunate that they used ai graphics

Unfortunate for who?

Kwyjor · May 5, 2026

Robert Newbie said:
I've always imagined a day where Star Fox runs at a solid, high framerate and plays flawlessly (no input lag).

Aren't there already hacks that do that?
https://www.romhacking.net/hacks/7163/
https://www.romhacking.net/hacks/6443/
https://www.romhacking.net/hacks/6333/

Robert Newbie said:
I know there are some SNES games that experience slowdown, but are there any Genesis games that have similar performance issues? My real question is: Which games would benefit the most from static recompilation?

I understand replacing the 68k CPU with a 68010 has been a popular fix for certain games, but I don't know the details offhand.

SegaGenesisRecomp gets first playable title: Sonic the Hedgehog

Well-Known Member

Well-Known Member

MediCat USB Dev

Well-Known Member

MediCat USB Dev

Well-Known Member

Well-Known Member

MediCat USB Dev

Well-Known Member

Jesus Saves!

Bubble Bobble Fan

Well-Known Member

Bubble Bobble Fan

Member

Well-Known Member

瓜老外

Well-Known Member

Similar threads

Popular threads in this forum