Sonic Advance bug list
From Sonic Retro
Path swapper glitch
Players using Sonic, Knuckles or Amy, can crouch near certain loop-de-loops with their back to them, wait for the camera to go down and move with the camera locked on that position, causing the map to lose its solidity. This can be reverted by triggering a path swapper, which is not easy to do because the ground is not solid as a result of the glitch. This glitch is useful to time attack Angel Island Zone Act 1 as Knuckles, and it can be seen in this video.
Tiny Chao Garden glitch
The Tiny Chao Garden mini-game has a major glitch. If the game data is deleted, rings obtained in the main game no longer transfer to the mini-game. There are two ways to revert this; using a video game enhancer such as GameShark or collecting the same number of rings that had been collected before the game data was deleted.