Super Smash Flash 2 Demo/Version 0.4a

Version 0.4a was the first iteration of the fourth major release of the Super Smash Flash 2 Demo, released on January 1, 2009, being the first version of the year of 2009. It added a new character: ; two new stages: and ; it was also the first version to add a new item: Capsule.

It is notable for being the point where the addition of characters was confirmed to have slowed down, with Gregory McLeod stating that the difficulty of adding characters had "increased exponentially".

Differences from v0.3c
Besides the new character, stages and item, it is possible to notice many differences from the previous versions; beginning with the possibility of adjusting the volume of music, sound effects and voice clips separately. Visual effects are also added to an attack when it hits, making it easier to know when a character lands an attack on another character (especially if said attack has low knockback).

Mario was recolored to match his appearance in Super Smash Bros. Brawl, and his Up Smash and Back aerial were also changed to resemble those he has in official Smash games.

The player can also choose to make a Team Battle, instead of the usual free-for-all match, but an option to enable team attack was yet to be added.

Aerial mobility got some attention, with tether recovery now being possible, but only for, at that moment.

As the capsule is not used by breaking it, basic item abilities got added, throwing, holding it, et cetera.