Sonic 3 & Knuckles
OriginSega Mega Drive / Genesis
TechnologyNative C/C++ port (engine reimplementation)
Available forWindows, Linux, macOS
View official projectAbout the project
Sonic the Hedgehog 3 es un videojuego de plataformas de 1994 desarrollado y publicado por Sega para Sega Genesis. Al igual que los juegos anteriores de Sonic, los jugadores recorren niveles de desplazamiento lateral mientras recolectan anillos y derrotan enemigos. Controlan a Sonic y Tails, quienes intentan recuperar las Chaos Emeralds para evitar que el Doctor Robotnik relance su estación espacial, el Death Egg, después de que se estrelle en una misteriosa isla flotante. Sonic 3 presenta a Knuckles the Echidna, el guardián de la isla, que pone trampas para Sonic y Tails.
Official project information
Sonic 3 & Knuckles — Recompiled
Play Sonic 3 & Knuckles on your PC, with Sonic, Tails and Knuckles. Optional mods bring in more adventures and let Mighty and Shadow join the fun. Separate versions of Sonic 3 and Sonic & Knuckles are also available.
Download and play
- Download your game's package from Releases. Choose Sonic3KRecomp for the combined game and the extra campaign options.
- Extract the complete Windows ZIP, then open the game. On Linux, make the AppImage executable and open it.
- Select your own matching game ROM in the launcher.
- Check your controls, then select PLAY.
Game files are not included. The combined game needs a Sonic 3 & Knuckles ROM; the separate versions need their corresponding ROMs. The v0.7.3 release provides Windows x64 ZIPs and Linux x86_64 AppImages for all three games.
The extra campaigns, Mighty and Shadow shown below were introduced in v0.6.0 as experimental, off-by-default options in Sonic3KRecomp.
New options in v0.7.0
These controls are included in v0.7.0.
In Mods, enable High refresh rate, then choose Presentation rate: 120, 144 or Display. Display follows the monitor's refresh rate. Gameplay and music keep their normal speed. Menus, finite special-stage views and some scripted scenes repeat complete frames. Blue Spheres uses the corrected widescreen projection by default when widescreen is enabled.
Enable Unfiltered audio for the clearer sound without the hardware low-pass filter. The normal filtered sound remains the default. Both controls are also available in the in-game options.
Gameplay options in Mods are optional and off by default. They apply to local play in Sonic 3, Sonic & Knuckles and the combined game:
- Infinite lives keeps at least three lives through death and retry, and preserves higher counts and life awards.
- Infinite time lets the clock run to 99:59 and stay there. The original 100,000-point bonus applies only during the actual 9:59 second; finishing at 10:00 or later gives the normal 100-point time bonus.
- Easier level select unlocks Sound Test on the title menu: select it with Up, then Start. In Sonic & Knuckles, hold the game's A button and press Start, keeping A held through the fade.
- Debug mode enables native placement controls in original stages: B enters/exits placement, A cycles objects and C places one.
- Shielded transformation lets native Sonic hold Up and press jump again in the air to become Super or Hyper with an elemental shield. The original emerald and 50-ring requirements apply. Ordinary shield actions remain available without Up; Mighty and Shadow keep their own controls.
- Sonic 1 checkpoint bonus stages, in the combined game, adds entry stars above activated imported Sonic 1 checkpoints when you have at least 20 rings. Jump into the stars to visit a native bonus stage and return to the checkpoint.
- Tails giant-ring follow, in imported Sonic 1 acts, lets a nearby companion run and jump after you into the end-of-act ring. He enters when he reaches it; distant or missing companions keep normal behavior.
Every zone, across the campaigns
The combined campaign brings together 46 zones, including the final boss areas. These are actual Sonic3KRecomp captures, mixing Sonic, Tails, Knuckles, Mighty and Shadow, including their Tails pairings. Imported stages use S3K movement and abilities. Extra campaigns and characters are experimental and require your own supported game inputs.
| Campaign order | Zones | Content |
|---|---|---|
| Sonic the Hedgehog | 7 | 19 acts, including Final Zone |
| Sonic the Hedgehog 2 | 11 | 20 acts, through Death Egg |
| Sonic CD | 7 | 70 act/time variants; Present, Past, Good Future and Bad Future |
| Sonic 3 & Knuckles | 14 | Both original campaigns, through The Doomsday |
| Sonic Megamix v3 | 7 | 19 acts, including Final Fight |
Expand a game to see every zone. Sonic 3 and Sonic & Knuckles have separate galleries below. Screenshots use 16:9 widescreen, except The Doomsday, which is shown at native aspect because its widescreen player rendering needs a fix. CD captions identify the time period pictured.
<details> <summary><b>Sonic the Hedgehog — all 7 zones</b></summary>Green Hill · Marble · Spring Yard · Labyrinth · Star Light · Scrap Brain · Final Zone.
Emerald Hill · Chemical Plant · Aquatic Ruin · Casino Night · Hill Top · Mystic Cave · Oil Ocean · Metropolis · Sky Chase · Wing Fortress · Death Egg.
Palmtree Panic · Collision Chaos · Tidal Tempest · Quartz Quadrant · Wacky Workbench · Stardust Speedway · Metallic Madness.
Angel Island · Hydrocity · Marble Garden · Carnival Night · IceCap · Launch Base.
Mushroom Hill · Flying Battery · Sandopolis · Lava Reef · Hidden Palace · Sky Sanctuary · Death Egg · The Doomsday.
Sunny Shores · Dark Fortress · City Outskirts · Misty Maze · Starry Night · Metallic Base · Final Fight.
Extra campaigns and characters
In Sonic3KRecomp, open Mods to choose your additions. Each has its own checkbox, and all are experimental and off by default.
| Mod | What you need |
|---|---|
| Sonic 1 stages | Your own supported Sonic 1 ROM |
| Sonic 2 stages | Your own supported Sonic 2 ROM |
| Sonic CD stages | Your own supported Sonic CD (US) disc image |
| Sonic Megamix stages | Your own Sonic Megamix v3 ROM |
| Mighty | The same Megamix ROM |
| Shadow | The same Megamix ROM |
Enable whichever campaigns you want. They play in this order: Sonic 1 → Sonic 2 → Sonic CD → Sonic 3 & Knuckles → Megamix. You can enable Mighty or Shadow without enabling Megamix stages. Selecting the Megamix files once fills them in for all three options.
For Sonic CD, select your disc under the mod's Files and wait for the import to finish before pressing PLAY. No Sega CD BIOS is needed for this mod. It uses Sonic 3 & Knuckles' characters and abilities. For the original Sonic CD experience, see SonicCDRecomp.
v0.7.0 and later: under a mod's Files, select your Sonic 1, Sonic 2 or Megamix ROM, or a ZIP containing that ROM. The bundled offline importer verifies it, prepares a private cached campaign and fills in the resources automatically. Each campaign needs only its own cartridge and your selected S3K ROM. A Megamix import also prepares Mighty and Shadow; their checkboxes stay independent. Wait for completion, then select PLAY. No Python or Pillow installation is needed with the complete package. Failed imports retain your previous resources and native progress.
The bundled importer also handles Sonic CD CUE/BIN, ISO, raw data BIN/IMG and verified .sgcd images, directly or inside a ZIP. Keep the CUE and its referenced tracks together to retain CD audio. Data-only ISO/BIN images provide stages, embedded Past music and voices; Present/Future CD audio requires the audio tracks. The importer reports missing CD audio and retains previously verified music when available.
Published v0.6.4: cartridge stage packs still need to be prepared before use. Follow the Sonic 1/2 setup guide, Megamix setup guide, or Sonic CD setup guide. Its CD import also needs Python and Pillow, as explained in its guide.
Make it your own
- Controls: set up your keyboard or controller in the launcher.
- Widescreen: fresh profiles default to Mods → Widescreen → Adaptive to fit the game to your window, or select a fixed screen shape.
- Knuckles & Knuckles: enable the mod and play as Knuckles with a crowd following you. Choose 1–74 extras; additional local controllers can join in. Available in Sonic 3 & Knuckles and Sonic & Knuckles.
Your progress
Use the game's normal save slots to keep your progress. When upgrading or moving the game, keep all your save files and settings together. Disabling an extra campaign or character keeps its progress for when you enable it again.
With extra campaign mods enabled, save states, rewind and online play are currently unavailable. Use the normal in-game saves instead.
Help and feedback
These optional campaigns and characters are still experimental. If something goes wrong, report an issue with your game version, enabled mods and a screenshot if possible.
Want to build or contribute? See the build guide and release guide.
Credits and license
TheGabeMaster29 contributed extensive QA testing, detailed bug reports, and regression feedback.
Sonic and the original games belong to SEGA. Campaign and character additions build on Sonic Anthology by sonsegajp (formerly SonicTrilogy), whose Sonic 1, Sonic 2 and Sonic CD work is adapted here with attribution, and on Sonic Megamix by Team Megamix. This project uses segagenesisrecomp. Project code is under the PolyForm Noncommercial license; third-party notices accompany the downloads.
<p align="center"> <sub><b>R.A.I.D. — Retro AI Development</b> · a Discord for AI-assisted retro reverse-engineering, decomp & recomp</sub> </p> <p align="center"> <a href="https://discord.gg/Ad9BwSzctP"><img src=".github/raid-discord.png" alt="Join the Retro AI Development (R.A.I.D.) Discord" width="200"></a> </p>