Sonic 1 Beta Hoax (Sonic Rom Hack)

In 1999, Cyan Helkaraxe wanted to stir up more interest in Sonic 1 among the Sonic community. He decided to do something which had never been done at that time: create a ROM hack. The resulting hack would become known as the Sonic 1 Beta Hoax. Cyan set to work on the Sonic 1 REV00 ROM, researching its internal workings primarily by a trial and error process, since there was absolutely no documentation on Sonic 1 available at the time. His goal was to create a hoax prototype a game that mimicked the behaviour of a "genuine" Sonic 1 prototype.   In May 1999, Cyan released his hack to Simon Wai's Sonic 2 Beta page. The ROM was deliberately not listed as a hoax; rather, it was released under the title "Sonic 1 beta?".   The release of the hoax prototype stirred up more interest in Sonic 1, and when it was identified as a hoax, Andy Wolan invited Cyan to the Sonic Stuff Research Group for his work in creating the ROM hack. Features The ROM header was changed. Specifically, the date was altered from April 1991 to December 1990 and the serial number was changed to "GM xxxxxxxx-xx". The SEGA sound is missing. This was done by shortening the ROM size to cut the sample off. Title cards are missing. The "GAME OVER" text when you run out of lives is absent. All music tracks have been edited to an extent. Specifically, they had their voices and sequences muted and/or altered to give the impression of a unfinished soundtrack. Only Green Hill, Sparkling, Starlight, and Final Fight work. All other zones aside from those mentioned crashes the game. This is caused by purposefully malformed data within those zones being read by the Mega Drive. Both Labyrinth and Clock Work Zone are inaccessible and crash the game. Level Select has 2 renamed zones. Final Zone has three stages (neither implemented) and boss has its own stage: Final Fight. Special Stage is called Special Zone (and not implemented). The sound test has several of its entries replaced with commands that crash the game. Zones are differently coloured. Green Hill Zone appears to be at an early stage in development. Sonic has a different palette. The ending sequence does not work. Beating the boss of some levels, including Green Hill Zone and Star Light Zone, results in the game crashing with an Address Error. Waiting on the Stage Select screen too long will cause the game to crash. The "TIME OVER" text doesn't appear on the screen when the player reaches 10 minutes. Source