This is a derail since I'm mentioning a port to Android OS instead of a console, but whatever. But I guess Ouya is kind of a like a console, right?
The Android OS version of Sonic 2 is way better than the original Genesis version.
One major improvement that makes the game more playable is that they fixed the Special Stages. In the original Genesis version, it was all pre-rendered with a choppy framerate that made it an unplayable fucking mess. You couldn't even see rings or bombs coming in the distance, and when they were in range it was too late to catch rings or avoid bombs, so you would have to memorize the Special Stages to OCD level detail. The Android version makes use of modern graphics hardware, and now the Special Stages are rendered in a real 3D environment, with 2.5D sprites representing objects. Now you can see rings and bombs in the distance so you can react in time.
Another improvement is that makes use of the 16:9 aspect ratio. So now you can see obstacles in front of you while running fast and can react in time, as opposed to running fast and running into spikes or those flying blade things those fucking ant robots shoot at you in Metropolis Zone because you couldn't see it coming in a 4:3 aspect ratio.
Sonic 2 used to be one of my least favorite of the Sonic games, until it came out on Android OS with all these problems fixed. Now I can fully appreciate this game since I can actually play it minus the bullshit high difficulty that came from Genesis technical problems, not game design problems. I guess the game was just ahead of its time. Maybe it would of played better if it were a Sega CD game?
The Android OS also has a different ending, but I'm not gonna spoil it. Also, an official Hidden Palace Zone that you can access through a hidden exit in Mystic Cave Zone.
The game only costs a few dollars. Also, it's probably the only game on Android OS worth playing....