If anyone's interested, I wrote up a review of the game for the site I work for. Based on finishing the single player, getting to level 20 in online multiplayer and about an hour with the split-screen. The review's quite long, around 1800 words, but then, it's an interesting game.
http://rubyhornet.com/video-game-review-splatoon/
http://rubyhornet.com/video-game-review-splatoon/