This is a list of updates to Mushroom Kingdom Showdown. This game has had thirteen different releases (including v0.1, which was not officially released; and the glitched releases that were later replaced).
MARIO Smash Bros. <v0.0>
On August 11th, 2014, the original concept for Mushroom Kingdom Showdown was released. It was called MARIO Smash Bros. at the time. This version features three playable characters; Mario, Wario and Bowser; and one stage: Mushroom Plains. At this point, Mario used a different sprite sheet, which was based on his Super Mario World. The title screen (and character select) was both different too, with a black and white stripy pattern. Other differences from the final game include different artwork for each character, and an announcer on the Character Select Screen.
Mushroom Kingdom Showdown <v0.1>
After the reception that MARIO Smash Bros. recived, a small update video was released, showcasing new content that would be added in the next update. Three more characters were introduced in this video - Waluigi, Kamek and Donkey Kong. Other changes include switching Mario's sprite to a sheet created by Gregarlink, and adding knockback.
(No Download Link available)
Mushroom Kingdom Showdown <v0.2>
Version v0.2 introduced four new characters - Luigi, Yoshi, E. Gadd (named Elvin at this time) and Shadow Mario, the first secret character in the game, and the first clone character. Two new stages were added - Platform Castle and Galaxy Island (both based on stages in the Super Smash Bros. series). The character artwork was changed to 2-D art instead of the 3-D art of previous versions.
Mushroom Kingdom Showdown <v0.3>
Four more characters were added in this update - Wart, Peach, Fawful and Petey Piranha; the second unlockable character. The menu was given a new design, still used in the final version. Three more stages were added to the game - Pipe Battlefield, Fawful Arena and Mario Bros. Computer Players (CPUs) were added to the game, but at this point, they were in a experimental state, and not complete. Each character now had a side-tilt and a dash attack.
Mushroom Kingdom Showdown <v0.4>
In this update, Classic Mode was added to the game with Master Hand, the final boss of the mode. The first item was added to the game - the Heart Container. Koopa was added as a playable character, and two more stages were added - E. Gadd's Lab and Dry Dry Desert. More balance changes were made to the game alongside the new content. Countdown and K.O. screens were added at the start and end of a battle.
Mushroom Kingdom Showdown <v0.5>
Two new character were added to the game - Bowser Jr. and Dr. Mario (the second clone character, and third unlockable). Mario, Luigi, Wario, Waluigi and Bowser were given Showdown Attacks - the equivalent of Final Smashes from the Super Smash Bros. series. An Options menu was added, allowing you to change item frequency and toggle Showdown Attacks on and off. The Heart Container was reskinned into the 1-Up Mushroom, and a Super Mushroom item was added. Other miscellaneous changes were made, including changing Elvin's name to E. Gadd, giving an alternate color to Player 2 and removing Master Hand from the game, temporarily replacing the fight with a random character.
Mushroom Kingdom Showdown <v0.6>
Two more characters were added to the game - Toad and WwwWario. Every character, including the new characters, now have Showdown Attacks. Two new stages were also added - Wario's Throne and Unknown Cavern. A new Solo mode - Target Smash!; was added, now appearing as a part of Classic Mode. Giga Bowser was added to replace Master Hand as the final boss of Classic Mode. Other changes were made, including a toggle for the amount of HP characters have, adding new effects for attacks, Hard-Mode CPU, Hard-Mode difficulty in Classic Mode, a redesign of Mushroom Plains, and fast falling.
Mushroom Kingdom Showdown <v0.6> (Glitched)
This is a glitched version of v0.6 that was released by accident. This version was replaced within hours of being released. Credit to user 854220 for the download link. Every time you enter a match it will end right after the countdown. Once you unlock S. Mario, the bug is fixed, but your HP will counter will only be at 5. Once unlocking either Petey or Dr. Mario, the health will go back to normal.
Mushroom Kingdom Showdown <v0.7>
A new character - Geno, was added to the game, alongside his own stage - Forest Maze. All characters were given alternate costumes, and Koopa was given a special "Dry Bones" costume. A new Hard Target Smash! stage was also added. The ability to Air Dodge was added to the game. More minor issues were fixed, and balance changes were made, such as Waluigi getting a new Neutral Special.
Mushroom Kingdom Showdown <v0.8>
Three new characters were added to the game (all being unlockable) - King Bob-omb, Diddy Kong and Shy Guy. Three new stages were also added - Peach's Castle, Bowser's Island and Jungle Japes. More costumes were also added to each character, including a "Dark Bowser" costume for Bowser. Other minor changes were made, including an update to the character select screen.
Mushroom Kingdom Showdown <v0.9>
A new character - Midbus, was added to the game. Dr. Mario, Shadow Mario, and WwwWario were moved over to a second screen on the Character Select. A new stage - Mario Circuit, was also added. The final new mode - Takedown, was added, based on All-Star Mode from the Super Smash Bros. series. Many fixes were made in this update, including a Donkey Kong respite, redesigns for Mushroom Plains, Wario's Throne, Bowser's Island and Platform Castle. This version had a few bugs, which were fixed in v0.9b.
Mushroom Kingdom Showdown <v0.9b>
This update fixed glitches found in the previous release, such as Mario Circuit being impossible to unlock because of a glitch in Takedown Mode where you cannot win, and the player getting stuck in an infinite loop while trying to unlock Diddy Kong.
Mushroom Kingdom Showdown <v1.0>
The full release of Mushroom Kingdom Showdown. King Boo was added, with a lack of Showdown Attacks or Costumes, due to a glitch that could not be fixed before release. Dr. Mario also recived updated sprites. He also released the source files, as a .MFA file (used with any Clickteam product). This allows users to mod the game.
This is the final update of the game, as creator WwwWario dropped the game after multiple unsolvable issues in the game arose, and to move on to different projects.