The first couple minutes are tutorial and a frustrating watch. I actually didn't have time to play Splatoon at E3 (Darren did), so it's nice to watch a whole match play out. And it's like playing Graffiti in Tony Hawk's Pro Skater but with guns (and squids) instead of skateboards (and squids).
I'm even more for the concept after the video. Despite the colors and cuteness, this seems like it could be a real challenge. I'm not sure how big the online scene could get, however, so it might just end up good local co-op fun.
Plus, there's a fat cat with a bow tie and suspenders who declares victors.
Fun fact: I am peering nervously at a squid in my avatar.