Screenshot from the menu of Sonic Megamix.
Sonic the Hedgehog Megamix, or more common, Sonic Megamix, was ported by pirates being the only Sonic hack ever released on the cartridge (Genesis and shit called "Mega Drive Portable"). Despite the game not being Russian, the game was also sold in the Russian market. As, for example, the game was ported possibly in 2010s, because Russians are always meant for pirates, or, they want to make money by doing that. Here's a non-roughly translated, first segment from the back of its cover:
SONIC MEGAMIX - is the remake of the first, good Sonic. In the game, not only Sonic participates, but the black hedgehog Shadow and the armadillo Mighty...
The cover art. Notice the "made in Russia" (Сделано в России) on bottom left.
Yeah, "made in Russia". Obviously refers to the cover art, but NOT the game itself. Also notice the FPS on bottom left of each magazine "picture". It is however, as I could say, made from Kega Fusion, one of popular Genesis emulators alongside Gens.
Look the right of the cover art. The game uses the modern Sonic art, but the game itself the classic one. As Shadow is modern-born, it looks somewhat like classic one in-game. Mighty is classic-born but looks modern on cover-art. So it could have been made after 2010, but not the hack. Its stable version 3.0 (last one for Genesis) was made way back in 2007.
As the story almost "forever" continues, this segment hasn't already finished yet...but better know that you should be away from pirates as this is COUNTERFEIT!!!!