Splatoon features several different game modes, including four-on-four online multiplayer and a single player campaign.

The concept was created by lead programmer Shintaro Sato, who had previously worked on games in the Animal Crossing franchise.

The development team for Splatoon was generally composed of younger Nintendo employees compared to other games by the company.

Splatoon received positive reviews, with critics praising Nintendo's decision to enter the genre with a new franchise, the game's overall style and presentation, gameplay mechanics, and its soundtrack.

However, criticism was directed at the exclusion of voice chat and private lobbies, the small number of multiplayer maps at launch, and issues with online matchmaking.

In humanoid form, Inklings can shoot ink in their team's color, which can be used to cover the environment or "splat" opposing players or enemies.

Each item carries an ability that improves the player's statistics, such as faster respawn time or longer special duration.

[20] Following the final Splatfest event, which ended on 24 July 2016,[21] Super Sea Snails can be earned by winning a certain number of matches.

[22] Octo Valley is the game's single player campaign in which players are recruited by veteran and leader of the Squidbeak Splatoon, Cap'n Cuttlefish to rescue the Great Zapfish, Inkopolis' source of power, from the Octarians, a race of octopuses with whom the Inklings warred in a century-old territorial conflict known as the Great Turf War.

Players use a default ink weapon for this mode, which can be enhanced with upgrades or power-ups by collecting Power Eggs littered across the campaign's levels.

In mid-2013, one member of the Animal Crossing development team, Shintaro Sato, created a four-versus-four ink-based territory control game set in a featureless arena.

[25] After management approved making the prototype into a full game, the team started expanding its concepts, creating the ability to hide in ink,[26] and wanted to somehow incorporate squids.

[30] Splatoon was revealed in a trailer during Nintendo's E3 2014 Digital Event video presentation, and a demo of its multiplayer mode was playable on the show floor.

[35] A collaboration with Masahiro Anbe's Squid Girl manga series was announced, which included free in-game costumes released on 6 August 2015.

[38] Nintendo UK partnered with Adrenaline Alley skatepark to decorate it with decals and props based on the game and install several Wii U demo stations for the summer.

[40][41] Wii U Deluxe Set bundles with Splatoon included were released in North America at Best Buy stores (as a coupon for a digital copy)[42] Australia, Europe, and New Zealand (on a physical disc).

Players who pre-ordered the game at GameStop received a download voucher for Splatoon-themed Mii costumes for use in Super Smash Bros. for Nintendo 3DS and Wii U.

[57] Additionally, Nintendo announced that Splatoon's online services will continue to be active, despite the game's final Splatfest having occurred on 22 July 2016.

Many in the gaming press were surprised that Nintendo was creating a shooter intellectual property and praised the new gameplay ideas that distinguished it from other titles in the genre.

[71] IGN initially scored the game 7.9, praising the gameplay but criticizing the low number of maps and modes at launch and absence of voice chat.

"[61] Nintendo Life scored the game nine stars out of ten, considering Splatoon one of the "most fun" online games available because of the unique way each online match played out due to the ink mechanic, which also helped counteract potential boredom from the low number of maps playable at launch.

[76] Writing for The Guardian, Kate Gray praised the visual style of Splatoon for contrasting realistic shooter games such as the Call of Duty franchise with a "90s cartoon aesthetic", citing influence by games such as Jet Set Radio, Super Mario Sunshine, and de Blob, along with a catchy soundtrack.

[95] An artbook for the game titled the Art of Splatoon was released in Japan in September 2015, and in North America and Europe in June 2017.

[106] In 2016, a series of real-life virtual concerts featuring the Squid Sisters, known as "Squid Sisters Live" and appearing as holograms, were held at Tokaigi 2016 (Makuhari Messe) in January, Choukagi 2016 in April, Japan Expo (Paris) in July, and Niconico Cho Party in November.