SA2B Tutorial: 99 Lives Glitch
This is a very easy glitch to perform, and very useful. While it's not good within a single-segment speedrun of the game, if you run individual levels this can be a real lifesaver. We use underflow of the lives counter and back ring abuse to get ourselves 99 lives in a pretty efficient way. You'll need Rouge's treasure scope and possibly her Mystic Melody. You can destroy the metal boxes with a correctly placed drill dive, though.