Backtracking is a common term used on games (also on SMF and SMF2) to refer the action employed by the player to return to an old place in order to open and pass through more ways which weren't opened before.
On these kind of levels, the level maker tries to close some paths on his level so the players need to find something (mostly an item) to be used to unlock or make the path possible and pass through it.
The backtracking action is frequently employed on puzzle levels, however it can be used on any other level type.
Usage in Super Mario Flash[]
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Usage in Super Mario Flash 2[]
This action is more noticeable on Super Mario Flash 2 due to its set of items and sprites that can be used in different ways to open or access to a specific path. The backtracking is also more possible here because the game allows the level maker to make a level on x and y axis.
One example of item usage is to find a key to return and throw it to a part with spikes so the player could jump and fall where the key is placed, Mario will keep standing on the key.
The usage of Palace Switches is frequently used on puzzle and backtracking parts and levels, turning them on and off will make blocks to appear or disappear, making possible a part to be accesed.
Power-ups usage is another kind of sprites the user could obtain to access to a part, a Fire Flower, for example, can be used to throw fireballs to enemies which didn't allow the player to complete a path.