Sonic 3 Unlocked
A large overhaul of Sonic 3 on the Mega Drive that adds Amy, Mighty and Ray as playable characters, an Encore Mode in the style of Sonic Mania Plus and a long list of fixes. The first public build is a demo made for the 2026 Sonic Hacking Contest.
What it is
Sonic 3 Unlocked is a long-running project by Liliam Bronze (liliambean), started in 2018, that tries to bring ideas from the modern Retro Engine releases back to the original Mega Drive cartridge game while still running on real hardware.
What's new
- Three new playable characters: Amy Rose with her hammer attacks, Mighty the Armadillo with a spike-proof shell and a ground-pound, and Ray the Flying Squirrel, who glides through the air. Their sprites are based on Sonic Origins Plus and Sonic Mania Plus, reduced to the Mega Drive palette.
- Encore Mode: two characters on screen at once, with swapping, rescued partners kept as stock lives and special item boxes such as Roulette, Change and the Combine Ring.
- Quality of life: skippable cutscenes and score tallies, Super forms moved to their own button, a barrier HUD, no more continue tracking, and per-section save erasing.
- Polish: many bug fixes from the original game, smoother animations and a new Super form for Tails.
Status
The current release is a demo prepared for the 2026 Sonic Hacking Contest; the Encore palette option, Encore special stages and a Museum are still to come, and the author plans a few larger releases as the remaining features are finished.
Playing it
Get the build from the author's GitHub page and follow the instructions there. Bug reports go to the repository's issue tracker.