Collection: WarioWare

9-Volt's stages in the WarioWare franchise only feature games and series developed by either the main Nintendo EAD teams or Intelligent Systems, meaning that some well-known Nintendo IPs such as Kirby and Pokémon are left absent from 9-Volt's microgames. There is one obscure exception to this rule that can be found in 9-Volt's cutscene in WarioWare: Touched!, where a Pokémon Pikachu LCD device can be seen among his Nintendo collection.

www.warioworld.com was an official Nintendo website made as a hub for developers and publishers licensed to work on Nintendo hardware. The site used Wario as a mascot, something that may not seem strange as his profession is designing video games in the WarioWare series. However, the site was opened in 1997, predating WarioWare by multiple years, and also predates the Wario World game for GameCube. Instead of renaming the site to avoid confusion and using the URL for the game's US promotional site, the URL www.wario-world.com was used for the game's website, something that more than likely caused confusion for Wario fans. WarioWorld was closed in 2016, having received very few visual updates since the 1990s, and now redirects to a more modern and professionally designed Nintendo developer hub.

In the cutscenes for Kat & Ana's stage in WarioWare: Move It!, Cractus from Wario Land 4 appears. This is the first time a Wario Land character has appeared in the cutscenes of a WarioWare game.

In the Japanese version of Move It!, Cractus has a slightly different name from the Cractus that appeared in Wario Land 4.

The latter game's Cractus was called フラワナ, or Furawana, a pun on "flower" and「罠」(wana, trap). The former that appears in Move It! however is called フラワニ, or Furawani, a pun on "flower" and「鰐」(wani, crocodile). This name change could mean the character was renamed, or the Cractus in Move It! is meant to represent a different individual from the same species.

Nintendo Treehouse did not expect the WarioWare series to receive more installments after WarioWare: Touched!. They also did not believe that the character Ashley would not make any further appearances in the Wario franchise as a whole, so they cast a random localization employee named Christine Peyser to play Ashley in the English version of the game instead of a professional voice actress. This would become problematic as the WarioWare series proved its longevity, with Peyser being forced to abandon projects to record Ashley's lines. Ashley, alongside the entire WarioWare cast sans Wario, would eventually be recast in WarioWare Gold.

Pyoro, the star of the game-within-a-game series that rivals Wario's microgames in the WarioWare series, is a parody of the Japanese malt chocolate ball brand Chocoball's mascot, Kyoro-Chan.

WarioWare, Inc.: Mega Microgame$! (and by extension, the WarioWare sub-series as a whole) evolved out of the Sound Bomber mode in Mario Artist: Polygon Studio, which pitted the player in various rapid-fire minigames incorporating their 3D models. Several developers at Nintendo R&D1 grew fond of the mode and decided to flesh it out into a full game. According to Yoshio Sakamoto in a 2006 interview, the decision to rebrand it as a Wario spinoff came about because "we couldn't think of anyone else who would be best for the role. Wario is always doing stupid things and is really idiotic, so we thought him and the rest of the characters would be best for the game." The project was initially worked on in secret, but was immediately (albeit flatly) greenlit once the developers revealed it to their manager.

As a remnant of this inspiration, the microgames "Crazy Cars", "Diamond Dig", "Repellion", "Wario Whirled", "Batter Up", "Mario Paint: Fly Swatter", "Hectic Highway", "Racing 112", and "Maze Daze" are all directly based on Sound Bomber's minigames. Additionally, the boombox interstitial that appears between microgames in certain modes is a modified version of the one from Sound Bomber.