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.

This is a hack of Sonic the Hedgehog for the Sega Genesis. It features gameplay in which the hacks objective is to find the single ring placed in each level and special stage. Levels and special stages cannot be completed unless this ring is found and the player will die if they collect it, get hit, and not recollect it. Some levels have been redesigned slightly which can assist with back tracking so the player can search for the ring in all parts of the level. Other features include:

*Two moves have been added that can aid in the search for the ring. This includes the spindash move, done by holding down and pressing jump, which not wind down if the player releases the jump button. The other move is a ring sense ability. This move allows the player to "listen" for the ring by looking up or down. If it is located within the same vertical "slice" of the level a chime will sound, and the screen will pan left or right depending on the rings position.
*Two new monitor types have been created. One which increases the time available by adding 20 seconds and a random power-up monitor which grants one of the other available power-ups.
*A reserve shield feature is also introduced which allows shields to be accumulating meaning that if more than one shield is acquired then the player will still have a shield if hit.
*Checkpoint behavior has been modified so that passing one checkpoint will deactive other checkpoints. This means that passing earlier checkpoints and still activate them. In the original game passing a checkpoint would simply disable earlier checkpoints. This means it is possible to pass any checkpoint and have it activate. If the player dies they will restart at this checkpoint no matter where it is.
*Giant rings to enter the special stages always appear at the end of levels after the ring has been collected. The giant rings have also been added to acts 1 and 2 of Scrap Brain zone. If the player fails to complete a special stage they will reenter that stage next time they enter the special stage instead of skipping it. If the player collects all Chaos Emeralds in the special stages the giant rings will still appear but grant 3 lives instead of taking the player into the special stage.
*SRAM is available for saving game progress. The title screen will change based on where the game was last saved. It is also possible to erase the save at the title screen to restart over.
*There is now unlimited continues.

The patch is in xdelta format. The ROM should be in BIN format.

Sonic The Hedgehog (USA_ Europe).md - NOINTRO
CRC32: F9394E97
MD5: 1BC674BE034E43C96B86487AC69D9293
SHA-1: 6DDB7DE1E17E7F6CDB88927BD906352030DAA194
SHA-256: 46160BAA06362C711C9F1A5017CB7371026444936C8AF5E93A78996CF32FF2A6

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