That´s one I at least heard of before. And I like the general idea even if it seems a bit confusing at the beginning.
And I played a little of Kid Chamelon at our local supermarket back in the day so that was certainly familar as well.
But seing me playing a Mario game and a Sonic game next to each other would be a difference like day and night in terms of displayed skills. 
I’m the same in reverse. When I watch people play Mario it looks so easy, but I really struggle! Especially with those bloody flag bits at the end of levels.
There are not much different than the giant rings in Sonic you get after having at least 50 at the ends of levels. Exept you can´t forget jumping up to them…ahem…
That´s where the rewind function of the emulation comes in handy, because everytime I run past the Robontik sign and see the giant ring above me I go: nooooooooooo…
But that would be cheating and if I ever would record anything I wouldn´t do that because everyone would see it.
I think I´ll me a video and call it “See me suck (and hear me curse) at Sega games”.
you know… you can run back (from off-screen) and still jump through the ring!
because… Sonic > Mario 
You mean I can redo the level as often as I want just like in Mario? That is awesome! So where is the overworld map in this awesome game?
Only if you do it very quickly, otherwise it goes to the stats screen.
Even better: there is no need to redo levels like in Mario!
(just helping you to catch that big ring, but if you want you can always reset the game and start over)
Luckily Sonic runs much faster than that fat plumber 
I hope you did understand that I only notice the ring (because I´m usually not keeping count if the number is 50 or above or not) when I ran past the shield by which time it is too late to go back, right?
Oh how I envy the mighty blast processing.
Not really… I’ll post a video tonight for you to demonstrate what I mean.
You can go back when the high score display is showing?!
patience little grashopper!
@Sushi’s right I believe. If by shield you mean the sign that spins, you can still run back.
Before the stats come up though - after a few secs it force-runs him off the screen and the high score comes up then.
I´ll take that as a “yes of course you doofus”.
So, what was so hard about explaining it like that, @sushi?
It wasn’t the explaining part that was difficult… 
(Don’t worry… I’ll be posting some help needed in the Nintendo thread later - after 8 years or so I am still stuck at world 4 of Mario on the DS and bugged that I even never got to play world 3. I would like to finish it some day. So let’s see how your explaining skills are 
)
Mario expert here (well, the newer ones, anyway)
Is that New Super Mario Bros? I’ll help!
That´s the spirit…
Even if I was familiar with DS Mario, I don´t think I would help you after all that. 
I´m the reverse…but aren´t I always? 