Sonic and Crackers

"Sonic and Crackers" also known as "Sonic Studium," was indeed a prototype game featuring Sonic the Hedgehog, which never officially saw the light of day as a completed product. This game was presumed to be in development sometime around 1994 and is notable for its unique gameplay mechanics that involved Sonic and Tails linked together by a pair of rings or "magical handcuffs" that stretched and contracted. Players would control the duo and use the elastic properties of the rings to navigate through levels, a mechanic that was later refined and used in "Knuckles' Chaotix" for the Sega 32X.

The game is only known through a leaked prototype, which exists in various states of completion. The levels are largely incomplete and serve more as a proof of concept for the engine than as fully fleshed-out stages. The ROM of "Sonic Crackers" has been widely circulated on the internet and is a popular item among fans for historical curiosity and as an example of the game development process.

In "Knuckles' Chaotix," which is considered the spiritual successor to "Sonic Crackers," the idea of characters being bound together was preserved, but the game featured Knuckles and a new team called the Chaotix instead of Sonic and Tails. It's a fascinating glimpse into the experimental phase of game design at Sega during the mid-90s when developers were testing the limits of the Genesis hardware and exploring new ideas for the upcoming 32X add-on.