Sonic the Hedgehog is a platforming action video game. Developed by Sonic Team in 1991, the blue blur himself would become one of gaming's universal icons, and became the first series to stand as a serious rival to Nintendo's Mario series, flaming the legendary console wars.

A classic 2-D side-scrolling platformer, you control Sonic, a blue-colored hedgehog that runs pretty darn fast across the stages (zones as they are called in the game). Scattered throughout the zones are golden rings that Sonic can collect, which allows him to not only take damage, but allow access to special stages. If completed, the special stage will grant Sonic one of six Chaos Emeralds.

Dr. Ivo Robotnik, an evil genius, realizes the power of the Chaos Emeralds, and wants them for himself. As such, Robotnik traps the innocent woodland creatures of South Island. In response, Sonic attempts to free the creatures and collect the emeralds for himself in order to stop Robotnik's plans.

The main goal of this hack is to improve the flow of the first Sonic for MD/GEN while keeping the original level design mostly intact, keeping the player on the move or occupied with something interesting as often as possible.
Initially meant to just do something about the slower segments in marble zone, and the elevators in spring yard zone, it later grew into something more, with changes to every act.

The hack works with the below rom in Kega Fusion, using the auto fix checksum option. It also works with the github disassembly rom.
It is compatible with Esrael's spindash hack, but not the spike bug & spindash one, and not with the recent bug fixes hack. However, it wasn't designed with either in mind.
You can send the author a PM (send it to PresidentLeever at RHDN) if you know how to fix this, or if you have any other comments that can help improve the hack.

See the readme for more info.

Changes:
*Tweaked ring, item, obstacle/gimmick, hazard and enemy placement (for better flow, less trial & error and more consistent difficulty)
*Tweaked moving platform positions and speeds (same)
*Tweaked speeds for some hazards (same)
*Alternate ways of traversing the slower segments in marble zone and spring yard zone
*Removed some points of no return and improved path connectivity either by removing doors or fans, or adding platforms (example: added platform path to beginning of starlight 3 so players who screwed up the one shot slope movement and/or following jump could get another chance to take the top path
*Easier jump at the beginning of spring yard act 3 (also moved a few rings to the beginning to avoid death from missing the jump)
*Better visual clues for some hidden paths and detours (for example the vanishing platforms in scrap brain 2 leading to the 1-up will spawn more frequently)
*Added enemy or hazard to a few uneventful segments ("boat" segments in marble zone, labyrinth zone 1 shortcut, moving platform path in spring yard zone, scrab brain 3 shortcut, etc),
*Added some second chance platforms in pits (green hill zone 2, marble zone 3, spring yard zone 3, starlight zone, scrap brain zone)
*Two new hidden paths near the top of the screen
*Two new somewhat hidden speed shoes monitors, and a shield in a hidden dead end path in spring yard zone which only had a few rings

Sonic the Hedgehog (JUE) [!]
CRC32: F9394E97
Size: 524 288 bytes