List of Super Mario Advance glitches
From the Super Mario Wiki
This is a list of glitches found exclusively in the game Super Mario Advance, a remake of Super Mario Bros. 2. For glitches found in the original game and possibly Super Mario Advance as well, see List of Super Mario Bros. 2 glitches.
NOTE: Unless otherwise noted, all names are conjectural.
Rolling Yoshi Egg
First, the player must go to World 2-2, World 3-1 or World 6-3 and play as Luigi. The player must have at least three hearts, and go into a jar containing a Spark Chaser. Once inside, the player has to pick up the Spark Chaser, and then jump, hit a Spark at the top and try to get to one side or the other (this part is easier the more hearts the player has in possession). The player can't do it with only two, as when they shrink and it won't cause knockback. Then, the player must carry it out of the jar. It will become a Yoshi Egg with the palette of the Spark Chaser. It will act the same way as the Spark Chaser, with the exception of being re-usable if it falls in quicksand.
Stuck in a Mushroom Block
This glitch best works in Fryguy's boss fight area. If the player slides underneath one of the flying Mushroom Blocks, and the player lets go of , their top half, will be trapped inside the Mushroom Block. The only way to get out of it is to slide back out.
Sliding Mushroom Block
The player needs a Mushroom Block and a low enough ceiling. The player should jump up while holding the block and throw it while the block is inside the ceiling. If done correctly the block will quickly slide through the ceiling and fall down a few blocks away.