The concept is like The Ring, but on your DS: a cursed game kills everyone who plays it within seven days. It looks from the scans like your character plays this game; but somehow, so do you. There's a fake retro RPG that will no doubt begin dripping with insanity effects, and even a fake DS menu through which you'll receive creepy messages.
We're not sure how the main game works, and how it interacts with all these little fourth-wall-breaking touches, but we're sure we'll find out soon. Square Enix is apparently releasing this in July.