The online tournaments will be split into three divisions -- Squid, Inkling and Octo -- to cater for different age groups and abilities. Eight teams will qualify in each league, creating a grand total of 24 at the Gfinity stadium.

Starting on July 11th, Nintendo will also be holding a competition for Splatoon-inspired fan art and cosplay. The best submissions will be invited along to The Splatoon Fan Fest too, where a panel of judges will select the winners. "Fans will also be given the unique chance to pick up exclusive Splatoon giveaways and prizes, including rare merchandise, exclusive artwork created by Splatoon's revered Art Director and a one off personalised Splat Champ winner's jacket," Nintendo teases in a blog post.

The event is further evidence of Splatoon's success. The game has sold over 4 million copies, making it one of the best-selling Wii U titles to date. Splatoon's popularity has spawned a concert with hologram versions of Calie and Marie, the game's popular "Squid Sisters." Merchandise has been produced imitating its water gun and lint roller weaponry. It's even possible to buy clothing inspired by the garments available in the game.

But Splatoon's time is fading. The title is more than a year old and Nintendo's stream of free DLC is coming to an end. In addition, Nintendo has confirmed that this month's "Splatfest" -- an online tournament where players represent themed sides, like pirates and ninjas, will be its last. With the Nintendo NX looming on the horizon, it's time for the company to move on, or start thinking about a sequel. The Great British Splat-Off, then, should be thought of as a last hoorah for a game that has sold surprisingly well. Or rather, well for a system with an install base under 15 million.