Special Stage 1
The special stages in Sonic 2 are a lot different than the one in the first game. This time, in order to access it, all you need to have is 50 rings when you pass a checkpoint and then jump into the ring of stars that forms just above it. Here, you have to go across a half-pipe collecting as many rings as possible. The game will tell you how many rings you have to collect before you reach a checkpoint. Fail to get enough rings and you're booted back out to the level. If you pass through the third checkpoint with the required amount of rings, then you earn yourself a chaos emerald.
Now, I've mentioned that I'm not going for chaos emeralds in this playthrough, and it's not because I don't like the special stages. No, it's because when you come out of one, everything is reset. This, unfortunately, includes how many rings you had. Now, in the video, I entered the special stage with 58 rings and came out with none. You can in theory go back and collect all those rings again, but that's just busywork.
The main reason I'm choosing to collect rings is simply because I'm not an experienced Sonic 2 player. I want lives. The easiest way to get lives is simply collecting 100 rings. So, once I've finished this (and 3 & Knuckles), I may go back to try and get all seven chaos emeralds to show off Super Sonic, unless I manage it in the next game.