We received a sketch from one of our researchers.
A giant weapon, created by the Octopus Army Corps, awaits you deep inside their underground base. It appears to use the Battery Catfish as its power source. In order to rescue the poor thing[s] from this fate, you have no choice but to take down the weapon while withstanding its powerful attacks.
Splatoon is a third person shooter with both a 4-on-4 multiplayer mode and a single player campaign. The game has you play as squids, shooting ink to take down the evil Octopus Army Corps. The game is expected to launch in Spring 2015.