2 is really bad lol. The smaller scale was pretty disappointing and the levels somehow play worse than the original.
SA1 isn't even bad. Like SA2, some sequences are definitely worse than others, but at least it has a hub world and like six unique campaigns. It feels like a legitimate adventure, traveling from one stage to the next rather than just viewing cutscenes.
SA1 is objectively bad. In Sonic's first level, you can fall through the ground within the first 10 seconds just by running forward, and his campaign, other than Gamma's, is the only one that can actually be considered good. Tails is just a retread of Sonic's, Knuckles' is boring, Amy's would be fine if she moved at a decent speed, and Big's is just bad.
The open world is empty, lacks direction, and are a drag to explore. It's not a good game.