An unlockable stage is a stage that is not available at the start of the game (unlike a starter stage), but must be unlocked. Like an unlockable character, it is required to accomplish a particular in-game feat and once completed, a message will be shown, telling the player that the stage has been unlocked.
List of unlockable stages
In Super Smash Flash
|Battlefield||Super Smash Bros.||Clear All-Star mode with any character.|
|Final Destination||Super Smash Bros.||Unlock all characters.|
In Super Smash Flash 2
For the final version, any information is unknown.
In demo versions
These stages were made unlockable when first introduced in their respective demo versions:
|Chaos Shrine||FINAL FANTASY||0.7||Unlock Black Mage.|
|Clock Town||The Legend of Zelda||0.8||Accumulate a total of less than 5 minutes with all starter characters in Target Smash.|
|Sand Ocean||F-Zero||0.8||Play 10 Versus matches with Captain Falcon.|
|Final Valley||Naruto||Beta||Clear event #12: Shadow Clone Showdown.|
|Desk||Chibi-Robo!||Beta||Clear event #26: Cleaning Duty.|
|Mushroom Kingdom||Mario||Beta||Complete Classic mode with any character for the first time.|
|World Tournament||Dragon Ball||Beta||Play 15 Versus matches.|
|Steel Diver||Steel Diver||Beta||With any character, self-destruct in Gangplank Galleon, Lake of Rage, or Planet Namek 20 times in the bottom blast line on a Versus match.|
|Devil's Machine||EarthBound||Beta||Select "Ghost" Ness and self-destruct three times on a Versus match.|
|Hyrule Castle (64)||The Legend of Zelda||Beta||Complete Classic mode with Link, Zelda, or Sheik on normal or higher.|
|Saffron City (64)||Pokémon||Beta||Complete Classic mode with Jigglypuff or Pikachu on any difficulty.|
|Metal Cavern||Super Smash Bros.||Beta||Complete Classic mode on hard or higher with any character, without using any continues.|
|Waiting Room||Super Smash Bros.||Beta||Play any Versus match with Sandbag participating.|
- ↑ Only in 1.0.0 beta.