JAH THE HEDGEHOG — source and credits

Personal, noncommercial fan modification. No affiliation with Sega, Jahmyr
Gibbs, the featured coaches or players, any NFL team, or the NFL.

Original game: Sonic the Hedgehog (1991), Sega.
Disassembly: Sonic Retro and contributors, v26.08.
https://github.com/sonicretro/s1disasm/tree/v26.08
Upstream presents the repository for informational and educational use,
prohibits commercial use, and claims no ownership of the original code.

Browser engine: EmulatorJS 4.2.3, GNU GPL v3.
https://github.com/EmulatorJS/EmulatorJS/tree/v4.2.3
License: vendor/emulatorjs/LICENSE.EmulatorJS
Readable frontend source: vendor/emulatorjs/src/

Genesis emulator: Genesis Plus GX, stable WASM build dated 2025-06-14.
https://github.com/EmulatorJS/Genesis-Plus-GX
https://github.com/EmulatorJS/build
License and component notices: vendor/emulatorjs/LICENSE.Genesis-Plus-GX
This core restricts commercial usage.
Runtime changes and hashes: vendor/emulatorjs/RUNTIME-NOTICES.txt

New character art: generated with the built-in OpenAI Imagegen tool, then
converted into original Genesis sprite tiles and mappings. The high-resolution
source contains sixteen poses; the game uses 88 original animation slots with
rotated and transformed variants. Original animation timing is retained.
The title screen uses a separate upright football-holding portrait. All eight
portrait slots share that same pose, removing the cyclic head movement while
preserving the title sequence and Start input.

Silver & Blue Arcade website artwork: Detroit skyline and Detroit / Green Hill
start-screen landscape generated with the built-in OpenAI Imagegen tool.
These illustrations are website presentation; the playable levels are unchanged.
Detroit Lions logo: Detroit Lions / NFL, from the official NFL media CDN.
https://static.www.nfl.com/t_q-best/league/api/clubs/logos/DET
Barlow and Barlow Condensed fonts: The Barlow Project Authors, SIL OFL 1.1.
Font licenses: assets/fonts/Barlow-OFL.txt and assets/fonts/BarlowCondensed-OFL.txt

Boss roster:
Green Hill: Matt LaFleur, Green Bay.
Marble: Kevin O'Connell, Minnesota.
Spring Yard: Ben Johnson, Chicago.
Labyrinth: Aaron Rodgers, Packers-era rival.
Star Light: Matt Patricia, Lions-era coach with the sideline pencil.
Scrap Brain, Final Zone, and villain ending scenes: Matt Millen.

Boss artwork was generated from photo and original craft references with the
built-in OpenAI Imagegen tool. Each craft is uniformly scaled to preserve its
rounded proportions and fitted around the original weapon attachments. Original
movement, attacks, collision, health, timing, and projectiles are retained.
Green Hill's wrecking-ball pivot, chain spacing, deployment, and swing remain
unchanged. Regular enemies retain their original artwork and behavior.
Green Hill audit: assets/lafleur-boss-manifest-v3.json
Full boss roster audit: assets/boss-roster-manifest-title-v5.json
Steady football title audit: assets/gibbs-title-manifest-title-v5.json
Boss preview: assets/lafleur-boss-preview-v3.png

The gameplay engine, levels, collisions, physics, music, and game progression
are from the original game. Original palette files are preserved; two arena-only
skin palette assignments add a highlight and retain the existing brown shade.
Player, scenery, and HUD warning colors are unchanged. Packed sprites respect the
original Genesis tile and sprite limits.

Pristine REV01 MD5: 09dadb5071eb35050067a32462e39c5f
Pristine SHA256: 1b7f6635bd713f37f3c2f44f302b872c2e3c5f56e63637918dad4637146900fd

Character-frame audit: assets/sprite-manifest.json
High-resolution character source: assets/gibbs-atlas.png
Additional character-art audit: assets/sprite-auxiliary-manifest-title-v5.json
Title, life icon, 1-up monitor, finish sign, continue avatars, and ending
sprites are replaced. Original textual Sonic branding remains.
Modified cartridge SHA256: 0f5a8f15154d121d479e12f564af12e92365a2e6f5bb89af7017cc8274af3f25