Sonic 1 was littered with so many glitches, annoying and unfair parts, areas where the pace is incredibly slow, and physics annoyances that I just don't think it's a good game.
A lot of games were like that back then. It's not a bad game, it's just dated.
But I respect your opinion.
Man I disagree, it'll always be a gem in my book, but I can agree that Marble Hill Zone for instance was the bane of my existence when I was smaller lmao.
Other than that, I can't recall any game-breaking glitches of the likes..?
Its kind of a Mega Man 1 situation actually, whereas Sonic 1 was stupid unfair (Mega Man 1) and Sonic 2 is amazing (Mega Man 2)