Sonic The Hedgehog (SMS NC Revision)

Sonic The Hedgehog (SMS NC Revision) is a Master System ROM hack that updates the classic 8-bit Sonic adventure with revised graphics, altered level layouts, extra slopes, Emerald-location changes, and several gameplay refinements. Created by Ninjacat25, the project first appeared in the Sonic Hacking Contest 2024 and reached version 1.13 in February 2026.

🦔 A More Detailed Take on 8-Bit Sonic

NC Revision starts with the 1991 Master System version of Sonic the Hedgehog. Ninjacat25 revised Sonic and Dr. Eggman's sprites, changed the artwork for several objects, and gave Green Hill Zone the most noticeable visual treatment. Rings, monitors, signposts, animals and interface elements also received graphical edits.

🌴 Green Hill Gets the Biggest Visual Work

Green Hill Zone receives the most substantial graphical changes.

You will notice revised scenery, object graphics and character sprites as soon as the first Act begins. Sonic and Dr. Eggman also have different shading and expressions. The title screen received a new “SMS” logo as part of the revision.

🏞️ More Slopes Change Familiar Routes

The hack makes level geometry one of its main areas of revision.

Additional slopes appear in several locations, including:

• Jungle Zone Acts 1 and 2
• Labyrinth Zone Acts 1 and 2
• Green Hill Zone
• Bridge Zone
• Sky Base Zone

🌊 Labyrinth Zone Comes in Two Versions

NC Revision has two versions because of Labyrinth Zone.

The standard version removes the original water physics and drowning mechanic. Later updates also removed water-related visual elements from this version so the presentation matches the new mechanics more closely.

A separate [Water] version restores:

• Water physics
• Water palette
• Drowning mechanic

💎 Chaos Emeralds Have New Clues

The six Chaos Emeralds remain part of the Master System adventure.

Unlike the Genesis game, the 8-bit version hides Emeralds inside the normal stages. NC Revision changes some of their locations and provides different visual guidance.

The Emerald in Labyrinth Zone Act 2 was moved. Scrap Brain Zone Act 2 also received additional Rings to help you identify the route toward its Emerald. Sky Base Zone Act 2 received layout changes and shield placement to help with its Emerald location.

The current version no longer uses the earlier extra Ring placement in Sky Base Zone Act 2.

🎨 Sonic Finally Gets His Red Shoes

Version 1.8 made one highly visible character change.

Sonic received his familiar red shoes. The creator had to rearrange colors within Sonic's palette to make the change work correctly. Other sprite palettes required adjustments as part of the process.

Sonic and Dr. Eggman also received further sprite edits in that update.

🕹️ The Original Sonic Formula Remains

NC Revision does not replace the fundamental platforming system.

You still run through side-scrolling stages, collect Rings, defeat enemies and search for Chaos Emeralds. The Master System version uses a simple two-button control system. Button 1 or Button 2 performs Sonic's jump and attack, while the D-pad handles movement and other directional actions.

When Sonic is moving, pressing Down performs his rolling attack. You can also look up or down in appropriate sections by using the D-pad.

🥚 Six Zones, Six Different Settings

The full adventure retains the original Zone structure:

🎮 Game Controls