S2HD

About

Sonic the Hedgehog 2 is a 1992 Sega Genesis platform game developed by Sega Technical Institute, in which Sonic and his new sidekick Tails race to stop Doctor Robotnik from powering his space station with the Chaos Emeralds, across faster and larger levels than the first game. S2HD is a community decompilation of Sonic 2 HD, a fan-made remake, reconstructed from its compiled .NET assembly using decompilation tools; it currently builds and runs, but only partially, with several reported issues in specific levels.

How it differs from the original

Because a required video library doesn't support modern .NET, the end-of-zone cutscene video no longer plays in this build, and several Hill Top Zone bugs remain, including invisible and non-damaging lava, lava that fails to load, and a screen-shake effect that persists until the player dies.

Getting started

A build guide is included in the repository for compiling the project from the decompiled source.

History

The initial decompilation was completed in about an hour, using one tool to extract the project and another to reference and fix the resulting code.

Known issues & limitations

• graphics: H.264 cutscenes do not play due to FFMPEG compatibility issues with modern .NET.
• graphics: Lava in Hill Top Zone Act 1 is not visible and does not do damage.
• graphics: Rising lava in Hill Top Act 2 does not load or spawn.
• gameplay: Shake effect and sound in Hill Top Act 1 and 2 persist after the rising lava section until death.
• graphics: Lava can unload its asset if the camera appears offscreen when it is not.
• The shake effect and sound effect in Hill Top Act 1 and 2 persist after the rising lava section; dying may stop them.
• Lava can unload its asset when the game thinks the camera is offscreen even though it is not.

FAQ

What is S2HD?

S2HD is an open-source decompilation of Sonic 2. Source code reconstructed from the original game's compiled binary, so the game can be understood, rebuilt and ported. The original game ran on Linux, Android and iOS.