In All-Star mode, the player must fight all 28 characters in the game roster. They are randomly selected each round, like in the Melee version. At the start, the player must fight one character, then advance to two, then to three. At the end, you fight 3 Mr. Game & Watchs with 8 lives each. When completed, you unlock the Battlefield stage. Similar to Melee and Brawl, there are three Heart Containers but instead these will only heal 100% of damage instead of the full restore heart containers in the previously mentioned games. Because of this, All-Star Mode is significantly harder in SSF than in Melee and Brawl.
In Super Smash Flash 2
This article/section contains information of a formerly confirmed feature.
The original source that confirmed the subject has otherwise become obsolete, outdated or deprecated and has yet to be re-confirmed by an official modern source.
All-Star was initially confirmed to return in Super Smash Flash 2 via the official FAQ posted in the McLeodGaming Forums, with some hints regarding the fighting order been randomized again like in Melee and SSF. This question has long been removed from the post, though.
As of v0.9b of the SSF2 demo, there are unused files in Super Smash Flash 2 pertaining to All-Star, including a button to start the mode.