Streets of Rage — Dreamcast port and remaster

A native Dreamcast (SH-4, KallistiOS) port of Streets of Rage 1, built from the original game's code rather than an emulator, with an optional enhanced graphics mode on top.

You need your own copy of the ROM. No ROM data, and nothing extracted from it, is in this repository.

Features

The original game, statically translated from the 68000 code to run natively on the SH-4, with the original music, sound effects and timing, two players and all eight rounds. 640×480 output.

Enhanced graphics, switchable at any time (docs/REMASTER.md):

• 2x art for every player, enemy, boss, weapon, item and effect in all eight rounds, with anti-aliased edges and smooth shading. Any frame can be replaced with your own hand-drawn art.
• Dynamic lighting. Shop windows, neon, lamps and fire in the backdrop become light sources. Characters are lit from the side the light is on, with shading across their body and a rim of light on the lit edge; fire, the bazooka's flame and hit sparks light what is near them.
• Shadows cast on the ground from those lights, swinging round and lengthening as a character walks past a window, plus a contact shadow that lifts in a jump. Light spills onto the ground below the wall.
• Particles: embers from fire, sparks and smoke from the bazooka, bursts from hits.
• Weather, per round: rain in two parallax sheets with splashes, wet ground reflecting the characters and the lights, haze and mist, light shafts through the fog, and lightning that flashes the scene and throws its own shadow. Rain on the street, the bridge and the lift; steam in the factory; nothing indoors.
• Smooth animation: in-between poses between the game's own animation frames.
• A remastered title screen.

Each of these is its own switch in the options menu.

Cheats: start at any round, choose lives, infinite lives, health and specials.

Screenshots

<p align="center"><img src="docs/screenshots/title.png" width="640" alt="Title screen"></p>

The same frame of Round 1, drawn both ways. The options menu switches between them at any time.

<table> <tr> <td align="center"><img src="docs/screenshots/compare-original.png" width="420" alt="Round 1, original graphics"><br>_{<b>Original</b>}</td> <td align="center"><img src="docs/screenshots/compare-enhanced.png" width="420" alt="Round 1, enhanced graphics"><br>_{<b>Enhanced</b>: 2x art, dynamic lighting, weather}</td> </tr> </table> <p align="center"><img src="docs/screenshots/closeup-art.png" width="840" alt="Close-up of the original and the 2x art"><br>_{Up close: the original pixels and the generated 2x art (lighting and weather off)}</p> <table> <tr> <td align="center"><img src="docs/screenshots/fire.png" width="420" alt="Police special fire lighting Round 2"><br>_{<b>Dynamic lighting</b>: the police special's fire lights the street and the characters, with embers}</td> <td align="center"><img src="docs/screenshots/lightning.png" width="420" alt="Lightning in Round 1"><br>_{<b>Weather</b>: lightning flashes the scene and throws its own shadow over the wet street}</td> </tr> <tr> <td align="center"><img src="docs/screenshots/lightning-lift.png" width="420" alt="Lightning on the lift in Round 7"><br>_{<b>Weather</b>: rain and a strike on the Round 7 lift}</td> <td align="center"><img src="docs/screenshots/flycast-two-players.png" width="420" alt="Two-player demo in Flycast"><br>_{<b>In Flycast</b>: the two-player demo with the bazooka}</td> </tr> <tr> <td align="center"><img src="docs/screenshots/options-menu.png" width="420" alt="Options menu"><br>_{<b>Options menu</b> (L + R): cheats and the graphics switches}</td> <td></td> </tr> </table>

All eight rounds, enhanced

<table> <tr> <td align="center"><img src="docs/screenshots/round-1.png" width="420" alt="Round 1"><br>_{<b>Round 1</b>: rain, wet street, shop windows and neon as lights}</td> <td align="center"><img src="docs/screenshots/round-2.png" width="420" alt="Round 2"><br>_{<b>Round 2</b>: wet ground under the bridge}</td> </tr> <tr> <td align="center"><img src="docs/screenshots/round-3.png" width="420" alt="Round 3"><br>_{<b>Round 3</b>: mist on the beach}</td> <td align="center"><img src="docs/screenshots/round-4.png" width="420" alt="Round 4"><br>_{<b>Round 4</b>: rain, mist and lamp pools on the bridge}</td> </tr> <tr> <td align="center"><img src="docs/screenshots/round-5.png" width="420" alt="Round 5"><br>_{<b>Round 5</b>: the ship, lit from its windows}</td> <td align="center"><img src="docs/screenshots/round-6.png" width="420" alt="Round 6"><br>_{<b>Round 6</b>: steam in the factory}</td> </tr> <tr> <td align="center"><img src="docs/screenshots/round-7.png" width="420" alt="Round 7"><br>_{<b>Round 7</b>: rain on the lift}</td> <td align="center"><img src="docs/screenshots/round-8.png" width="420" alt="Round 8"><br>_{<b>Round 8</b>: the mansion}</td> </tr> </table>

Gameplay frames are from the host preview of the enhanced renderer (the same integer scene the Dreamcast draws; see docs/REMASTER.md); the menu and the two-player demo are Flycast window captures. Smooth animation is not shown: it needs motion, and few in-between poses exist yet.

Status

• Round 1 matches the original ROM frame for frame in emulation, including the boss, weapons, continue/game over and two-player play (docs/FIDELITY_GATE.md). Rounds 2–8 run to the ending but have not been compared with the original.
• The enhanced art is generated from the original frames; hand-drawn art is not started. Smooth animation has few in-betweens yet.
• Full speed with no audio dropouts in the recorded Flycast tests. Initial real Dreamcast tests reproduced and fixed missing title geometry; full hardware performance and playthrough validation remain open (docs/HARDWARE_TESTS.md).

What you need

• The ROM: Streets of Rage / Bare Knuckle (World), revision 00, 524,288 bytes, as a plain big-endian Mega Drive dump (no header, not byte-swapped). SHA-256 dd44f120446654bb91c448762f3e0cd0d9b034f35d0e3266a4dc34402ada95c0. Other revisions are rejected. Put it here:

  original_rom/Bare Knuckle - Ikari no Tetsuken ~ Streets of Rage (World).md
  

  Or pass its path as the first argument to the build scripts.

• KallistiOS with an SH-4 GCC that includes C++ (enable_cpp=1 in kos-chain). The scripts source ~/.local/share/dreamcast/kos/environ.sh; set KOS_ENV if yours is elsewhere. Versions used: docs/TOOLCHAIN.md.

• mkdcdisc (gitlab.com/simulant/mkdcdisc) to make the disc image. Expected at build/mkdcdisc/build/mkdcdisc, or set MKDCDISC.

• Python 3.14 (python3.14 on the path, or set PYTHON) for code generation.

• Flycast, or a Dreamcast with a GDEMU (or similar) or a burned CD-R. tools/run-flycast.sh launches Flycast on macOS, looking for Flycast.app in ~/.local/share/dreamcast/flycast/ then /Applications/ (set FLYCAST_BIN).

To see what is set up and what is missing, with where to get each thing:

tools/check-requirements.sh all

The build scripts run the same checks. The first build also clones the research repositories listed in tools/upstream-lock.json into research/.

Build a disc image

./build-cdi.sh

This writes dist/sor.cdi. Copy it to your GDEMU card, burn it, or load it in Flycast; on macOS:

./tools/run-flycast.sh dist/sor.cdi

dist/ contains your game data; don't share it.

Quick run without a disc

Builds an ELF with the ROM embedded and launches it in Flycast (macOS):

./build-and-run.sh

Flycast starts muted; FLYCAST_MUTE=0 ./build-and-run.sh plays sound. Serial output goes to build/logs/flycast.log.

For the real Dreamcast, build and upload through dc-tool-ip with an optional Shelly power cycle and local network discovery:

tools/run-dreamcast.py --power-cycle --discover

This waits for GDEMU/openMenu and dcload-ip, then keeps the console/fileserver attached. Hardware screenshots, replay testing, device addresses and overrides: docs/HARDWARE_TESTS.md.

Enhanced graphics

The art package is built from your ROM (about two minutes):

tools/build-headless.sh
tools/build-profile-core.sh
python3 -m venv build/tools-venv && build/tools-venv/bin/pip install numpy pillow
tools/make-art-set.sh

Once build/art/SORART.PAK exists, build-cdi.sh puts it on the disc and build-and-run.sh embeds it in the ELF. The disc build starts in original graphics unless built with SOR_ENHANCED=1; build-and-run.sh starts enhanced unless SOR_ENHANCED=0. Using your own art: docs/REMASTER.md.

Controls

Dreamcast	Action
D-pad	Move
X	Attack
A	Jump
Y	Police special
Start	Menus / pause
L + R	Options menu

The same mapping works on port B for player 2.

L + R opens the options menu at any time, including mid-game (the game pauses). Up/down selects, left/right or A changes, B / Start / L + R closes.

• Start round (1–8) and starting lives (1–9), for the next new game.
• Infinite lives / health / specials, for both players.
• Graphics (original / enhanced), Animation (original / smooth), Lighting (original / dynamic), Weather (off / on).
• Restore defaults.

Settings last for the session. Dynamic lighting is on by default (with enhanced graphics); SOR_LIGHTING=0 at build time starts without it. SOR_SMOOTH=1 and SOR_WEATHER=1 start with those options on.

Tests

tools/test-host.sh
python3 tools/test-rom.py
python3 tools/test-generation.py

tools/test-host.sh builds and runs the host tests under the sanitizers (after tools/build-headless.sh has staged the sources); one or more names selects a subset. Roadmap and known limitations: TODO.md.

Comparisons against the original ROM and benchmarks: docs/REFERENCE.md, docs/CADENCE.md, docs/AUDIO.md, docs/OPTIMIZATION_LOG.md. Progress: docs/PROGRESS.md. Hardware checklist: docs/HARDWARE_TESTS.md.

Licence

Original code in this repository is MIT. The game, its ROM and anything generated from it (translated code, extracted frames, art packages, disc images) are not covered by this licence and must not be redistributed.

The build fetches the inputs pinned in tools/upstream-lock.json into research/ rather than redistributing them: the Streets of Rage recompilation and MegaDriveEnvironment (MIT; ymfm BSD-3-Clause and the Suzuki Plan Z80 core MIT within it), RageDecompiler and the sor-disassemblies repository (no licence stated), and Genesis Plus GX (non-commercial), which is used only by the host analysis tools and is never linked into the game. The notices in licenses/ cover what a built disc contains (KallistiOS, the recompilation, MegaDriveEnvironment, ymfm and the Z80 core).