Classic

Classic mode is a single-player mode in Super Smash Flash and Super Smash Flash 2, where the player fights in a series of battles, one after the other, also participating on bonus rounds and culminating with a fight against Master Hand.

In Super Smash Flash 2
Classic mode was confirmed during the second McLeodGaming Direct. It is similar to previous iterations of Classic mode and include 10 levels in all:

Trivia

 * It was originally planned for Classic mode in SSF2 to have a new twist called the "Peril Roulette". As seen in the second McLeodGaming Direct, this feature would have given advantages to the opponent or handicaps to the player, depending on the difficulty setting.
 * According to developer, TSON, this feature has been dropped from the game and will not be included in a future update.