Sonic Hybrid RSDK

Aims to mix different Sonic the Hedgehog games into a single big game.

Start from here

This guide is useful if you never downloaded the project or if you want to start from scratch.

1. Download the latest release

2. Unpack the zip file

3. Paste in the directory rsdk-source-data the following files:

   • Data.rsdk from Sonic CD as soniccd.rsdk
   • Data.rsdk from Sonic 1 as sonic1.rsdk
   • Data.rsdk from Sonic 2 as sonic2.rsdk

4. Install .NET 6

5. Open a terminal and run the command dotnet run --project SonicHybridRsdk.Build

6. Put the RSDKv4 engine in the sonic-hybrid folder

7. Run the RSDKv4 executable and have fun!

Perform an update

This guide is useful if you previously played Sonic Hybrid but you want to perform an update. Please look at the commit list to know more info about the changelog through each update.

1. Download the latest release

2. Unpack the zip file and overwrite all the existing files

3. Open a terminal and run the command dotnet run --project SonicHybridRsdk.Build

4. Run the RSDKv4 executable and have fun!

Features

• Play Sonic 1, Sonic CD and Sonic 2 in a single big game.
• Star Posts in Sonic the Hedgehog 1 and CD will bring you to the Sonic the Hedgehog 2 special stages.
• Completing Sonic the Hedgehog 1's Final Zone will bring you to Palmtree Panic Zone.
• Completing Sonic the Hedgehog CD's Metallic Madness Act 3 will bring you to Emerald Hill Zone.
• The Stage Select in the debug menu will report all the implemented level names.
• Sonic CD stages correctly transitions as the original game.
• Metal Sonic is now a playable character.

Known bugs

• Sonic 1 Special Stages are working from the Stage Select, but the graphics is corrupted.
• The main menu of RSDK will report the wrong stage names.
• The Giant Ring from Sonic the Hedgehog 1 will teleport to the Sonic the Hedgehog 2 special stages.
• Collision Chaos and Stardust Speedway are half-implemented.
• Tidal Tempest, Quartz Quadrant, Wacky Workbench and Metallic Madness are barely implemented.
• In Palmtree Panic Zone, the spinner will softlock the player.
• Some Sonic CD's enemies and gimmicks might have the wrong palette.
• Playable Metal Sonic has a "rolling" bugging collision.

Resources

I written some notes on how to convert RSDKv3 scripts to RSDKv4 scripts without modifying the RSDKv4 engine.

Everything contained in rsdk/Scripts is a modified version of Rubberduckycooly's Sonic 1/2 script decompilation. This project would not exist without it.

The function SonicHybridRsdk.Unpack12/DecryptData was written by Giuseppe Gatta (nextvolume) from its Retrun.