Needlemouse: The Emerald Hills (lost build of unreleased 2D platformer; 2009-2012)
From The Lost Media Wiki
Needlemouse: The Emerald Hills was a planned 2D freeware platformer based on Sonic the Hedgehog.
The game was brought to attention when concept art for it was confused for SEGA's "Project Needlemouse" (later named Sonic 4). They later clarified the games were entirely different. In 2012, the game was said to be "on the backburner", and no information was revealed about the game since, leaving the game's status a mystery.