Hit by Caterkiller even though rolling (I hate this guy so much)

Killed even though I picked up rings.

Skidding Forever (I don't think you can do this in the mobile versions because of the different skid animation)

Death by scrolling screen:

Skipping lava sequences. There's only one block-ride sequence that can't be skipped.

I like this one in particular. You can still go back for the items.

And of running back on the screen at the end of a non-boss level. You can do this in Sonic 2, too. But not in the mobile versions. I kind of assumed everyone knew about it but I guess maybe they didn't!

I made these with a cool free program called GifCam.