SMS Sonic 1 is a great game, the later ones are probably best avoided IMO (although some would disagree). Nostalgia is a major factor here, the vast majority of games I map are games I've played through many times, on a real console, in my mis-spent youth. That's why I like to map the lame SMS ports rather than the originals - not so much "why the hell did I map *that* crap!?" as "someone will have valid reason to map the original and mine will become an ignored footnote, yet I don't care".
Others, like the Wonder Boy games and Sonic 1 8-bit, are really just great 8-bit design, something rather lacking as it was a generation that went from small, sparse levels up to backports of the big-money 16-bit titles of the 90s and missed out on having many big-money well-designed "proper" efforts in the middle.
I did spend a few hours trying to hack Sonic 2 similarly but it didn't come to anything much. These kinds of games really benefit from hacks to free-scroll the camera. I may try another hack to give infinite rocket sneakers and then try for a no-clipping mode. Having Sonic moving that fast will make mapping something of a challenge, of course...
