First released in Japan in 2005 for the Nintendo DS and released the year after worldwide, Electroplankton is a music game created by Toshio Iwai because of his interest in the system and its unique interface. The game has a very simple concept, where the player is able to make music by interacting with ten different species of plankton. Most of the game's material is in Performance Mode where the player is able to interact with the plankton directly. The game also features an Audience Mode in case the player just wants to set the system down to hear some music. The game notably did not include a save feature. This minimized the game's experience by eliminating menus and also made it more of an improvisational experience. In 2009 every mode in the game would get a re release on DSiWare where each individual mode came out as a separate app. The game would also get representation in Super Smash Bros. where the Hanenbow mode was a playable stage.
- Tracy: The player draws lines on the touchscreen and the plankton swim along to follow it.
- Hanenbow: Plankton bounce off leaves which the player can drag around with the touch screen. This mode would become a stage in Super Smash Bros. Brawl and Super Smash Bros. Ultimate.
- Luminaria: Four plankton follow arrows around a continuous path and the player can touch the arrows to change their direction.
- Sun-Animalcule: The player places plankton eggs and they emit sound as they hatch and grow.
- Rec-Rec: Four fish swim along and the player can record sounds with the microphone for them to play back.
- Nanocarp: The player can clap and speak to the plankton to make them change shape and respond with sound.
- Lumiloop: Four ring-shaped plankton that emit a continuous sound when the player rotates them.
- Marine-Snow: Even rows of snowflake-shaped plankton that make sounds when touched and stirred up.
- Beatnes: Long lines of plankton that play old-school songs and remember the sound effects you select.
- Volvoice: Allows the player to record their voice with the microphone and then distort it.
- No Plot? No Problem!: The game has absolutely no proper story or goal, instead being a tech demo where the player makes music by manipulating plankton in different ways.
- Nostalgia Level: The Beatnes plankton uses retro sounds and music from the Nintendo Entertainment System and several games on it like Super Mario Bros. and Ice Climber.
- Ridiculously Cute Critter: Never have planctonic creatures looked so adorable. Look at their smiling faces!
- Seldom-Seen Species: Plankton by itself is rather rare to see in fiction (other than in SpongeBob SquarePants), but you'd be hard-pressed to see anything but this game specifically featuring an actual sun animalcule.
- Tech Demo Game: Toshio Iwai created this game specifically because he had an interest in developing for the Nintendo DS and its unique interface.