Copper Test, and Sonic’s first stage in Java.

Two separate experiments now have their own pages: our original Copper character, and an editable Java reconstruction of Green Hill Zone Act 1.

Play Copper Test ↗ Play Sonic Lighting Test ↗

Copper has a name and a home.

The standalone Copper Test retains our copper-orange tenrec, source-based movement and camera study, controller mapping and supplied lighting/weather presentation. Lens flare uses a screen blend and adjustable strength; the Flare preview selects clear sunset lighting. Copper’s reference course is still an experiment with known incomplete object/event behavior.

Copper running through the original reference terrain

The first Sonic act, implemented in Java.

Sonic Lighting Test runs from the normal start through the signpost and act-clear tally. Java owns fixed-point movement, terrain sensors, camera, the 214 original object placements, 155 ring positions, enemies, powers, checkpoints, damage, lives, animation and results. TeaVM compiles the editable Java source for the browser. The original emulated preservation player remains available on its existing page.

The stage draws original Sonic mapping frames, object art, animated terrain, palette cycles, HUD and result cards from the supplied REV00 cartridge. Original music uses its verified sample-based loop points. Keyboard, touch and standard or mapped HID controllers feed the same Java input bits. No enemy damage hitbox, ring retention and unlimited lives remain three separate optional assists.

Original Sonic frames and scenery rendered by the Java reconstruction at the Green Hill loop

What the release tests establish.

A deterministic ordinary-input route reaches the act’s end in 2,960 updates, with 51 rings, three lives and no damage, deaths, assists or teleports. All 2,961 snapshots match between the desktop JVM and actual browser-compiled TeaVM engine. Independent comparisons cover selected native movement/camera/animation/power sequences, 7,952 terrain queries and 133,108 object comparison fields.

The same ordinary inputs also reach the signpost and exhaust the bonuses in the unchanged original ROM. All 32,571 comparisons of the eleven reported player-movement fields match; ring and life counters match throughout. One camera snapshot and the original graphics-loading delay before the tally remain explicit comparison limits.

Native Canvas checks draw the original frames, stage regions, result cards and lighting variants. The actual page module also passes keyboard, controller, pause, single-step and restart checks with DOM stubs. Interactive browser and physical controller play have not been independently verified: local browser automation is disabled in this environment.

Scope and remaining differences.

This release contains the first act; later acts, the title/menu boot flow and playable special stages are outside it. The exact original post-title oscillator/animation phase and loading delays are not independently reproduced. Selected comparisons and a completed Java route do not prove every possible playthrough or rendered hardware limit identical to the cartridge.

Audio uses original prerecorded command renders rather than a live Genesis sound synthesizer. Channel contention and some interruption/tempo behavior remain presentation approximations. Lighting/weather are new visual effects, using the supplied sky artwork and material metadata; they do not change the Java physics or stage timer. The Original preset restores native presentation.

Original cartridge bytes, earlier frozen releases, existing media and the original player’s save storage are preserved. These new experiments do not read or write those saves.

Java source, controls and fidelity notes ↗ · Release verification ↗ · Java source download ↗ · Copper source download ↗