Unlockable character
From McLeodGaming Wiki, a wiki about McLeodGaming
An unlockable character is a character that is not available at the start of the game (unlike a starter character), but must be unlocked. Unique criteria must be met in order to unlock a certain character. In Super Smash Flash, typically, the player must accomplish a particular in-game feat and once complete, a message will display: "Warning! Challenger Approaching!" with a white question mark block of the mystery character that he's about to face. By winning the challenge and defeating the opponent, the character becomes playable. All unlockable matches takes place in Final Destination. In Super Smash Flash 2 it will be the same although the tasks the player must complete to unlock the characters are still unknown.
Super Smash Flash
| Character | How to Unlock |
| Blue | Clear Adventure Mode with Blade on at least Normal difficulty. |
| Cloud | Complete 100-Man Melee with any character. |
| Crono | Clear 3-Minute Melee with any character. |
| InuYasha | Clear Adventure Mode without losing any lives. |
| Jigglypuff | Clear Adventure Mode on any difficulty with any character. |
| Lloyd | Clear Adventure Mode with any character after having one hour of total play time on Adventure Mode. |
| Luigi | Clear Adventure Mode with Mario on at least Normal difficulty. |
| Mewtwo | Clear Adventure Mode with Pikachu and Jigglypuff on at least Normal difficulty. |
| Mr. Game & Watch | Clear Target Test with every character but him. |
| Mr. Incredible | Clear Classic Mode with the original 13 characters. |
| Naruto | Clear Adventure Mode with the original 13 characters. |
| Shadow | Clear Adventure Mode with Sonic, Tails and Knuckles. |
| Super Sonic | Clear Classic Mode with Sonic on any difficulty without getting Game Over. |
| Young Link | Clear Classic Mode with Link on any difficulty. |
| Zero | Clear Adventure Mode with Mega Man on at least Normal difficulty without getting Game Over. |
Super Smash Flash 2
The following list is a prediction made by the SSF2 developers, note some characters that are listed as unlockable may end up being starter characters and vice versa, this list is not final.
| Character | How to Unlock |
| Blue | Unknown. |
| Captain Falcon | Unknown. |
| Falco | Unknown. |
| Jigglypuff | Unknown. |
| Kratos | Unknown. |
| Luigi | Unknown. |
| Mewtwo | Unknown. |
| Mr. Game & Watch | Unknown. |
| Renji | Unknown. |
| Riku | Unknown. |
| Sasuke | Unknown. |
| Shadow | Unknown. |
| Snake | Unknown. |
| Spikeman | Unknown. |
| Vegeta | Unknown. |
| Zero | Unknown. |
