[btbam1]

I've been thinking of doing a glitchless run of sonic 2, but I'm curious as to what defines a glitch. i'm only asking this because of levels like oil ocean act 1 where one can roll through various platforms to benefit the route.

[Aitamen]

Various intents on the word, we've ranted in circles about what entails a glitch. 

I say, do whatever feels right to you.  Alternatively, the best other course I've heard is "If it doesn't make sense in-world, then it's a glitch", which means that, yeah, 'Sonic could duck under the oil for a bit and shake it off after, no biggie, as long as he doesn't breathe it' could still be considered glitchless.

For me, most of the game's physics are accidental, so I don't bother distinguishing, but if you do, go for it.  Best of luck.