Wow. Great co-op multiplayer, and can even play with four people and only two controllers!
Story mode is basically this: You have a time limit and you can pick up different timeclocks to increase your time. Cookie is on the left side of the screen and Cream is on the other side, so you're separated perminantly, but sometimes you can't progress through levels unless your partner does something on their side. So there are lots of puzzles and stuff, and there are a couple types of monsters I've encountered. (By types I mean behavior types) There are random monsters that fly and then if you take too long to move they attack you, but if you can jump on it's head it'll die. :D There are also ground monsters that you jump on, also.
There are also level bosses that you help each other out to defeat.
But that's pretty much the story mode, very co-op.
Then there's also multi-player VS. which can have up to four people (with two sharing a controller). Apparently you can also use a multitap so everyone gets their own controller, whichever is easier. ^_^; I only played a round of VS. against myself, which wasn't very fun because I kept getting my characters mixed up. x_X;; But you apparently collect stars as you kinda "race" (slowly), and pick up powerups that make you big, small, speed boost (but lose points while going fast), etc.
It's pretty damn cute, too. The graphics on the case look pretty bad, but the game's always zoomed out so it's no big deal. It's also funny. In the intro Cookie and Cream are confronted by... A CHICKEN! WHO IMPLANTS A TULIP IN COOKIE'S HEAD AND AN UMBRELLA IN CREAM'S! AND THEN TELEPORTS THEM!
WHEE!
And the music, I suppose can get on your nerves, but I love it. >D It's kinda cartoony with weird... vocals... like Cookie is singing or something. :D
But yeah, at this point I've only played a couple of hours, but I'm really excited about it already.