>>717093424
-Super Sonic was a dumb addition that trivialized the game (especially when you get him in Emerald Hill Zone).
-The way you get into special stages was dumb, you actually had to play well in Sonic 1 to get into them.
-Spin dash trivialized getting speed, something that you needed to actually get good at in Sonic 1
-More levels, but some of them are boring (like the palate swapped Hill Top Zone)
-Gimmick levels (like Sky chase)
-Bad/broken levels (like Wing Fortress Zone)
Sonic 1 does have some rough edges, but overall it's a much better designed game. 2 (and 3) wanted to give players the feeling of speed without having to earn it.