Onion Rings are bad for you, as demonstrated in this very lengthy Sonic Sez segment. That's what it is, honest.
Hack by Captain Bozo and Ranger! Get it here: http://info.sonicretro.org/Sonic_2_XL
As this game is quite difficult, I have employed MASSIVE CHEATS. Technically, my lives are not infinite, I just always happen to have 88 of them. But 88 isn't infinity at all. I also used save states on the worst part. I am sorry for this thing. Oh god, so sorry.