the challenge levels were hard
security hall took me around 20 tries
meteor herd and mad space were hard as balls
time limit mode on radical highway was too
as was "very hard mode"
and other than that the game is quality
the challenge levels were
1. not too hard once you actually put effort in them
2. were god-awful: they were all terribly designed. collect 100 rings while avoiding the never-ending gunfire as eggman or tails! find the lost chao, but you need a million hidden powerups first! time attack was okay, and "hard mode", aka cheap death generator
the game has a lot of flaws. i actually like sa2 and that's probably because it was one of the games i played the most in my childhood, but i can perfectly understand people's criticism on this game. this game was amazing back then: right now, it's okay. this game does have some moments with awful designing but it's not terrible and i don't hate it.