Like Bub and Bob... oh wait, actually nothing like them.
One of the coolest games I tried at GDC this year is Ibb and Obb, a cooperative game for the Playstation 3. Ibb and Obb is almost dangerously cooperative, maybe desperately or potentially frustratingly cooperative, depending on how attentive the other player is. Suffice it to say, you gotta get a buddy who doesn't suck to play this with you.
The game is a cooperative platform puzzler. Ibb and Obb are two blob-like creatures with feet, one purple and the other lime green, who inhabit a world world divided in half; above the ground the gravity is normal (down), but below the gravity is reversed (up). The puzzles in the game often involve having to divide between the two via a hole in the floor. Neither Ibb nor Obb can jump very high, so sometimes in order for one to move on to the next section, they have to stand on the head of the other and jump onto the next platform, and usually the one below needs to take the lower, upside-down part of the level until the puzzle can be solved, before the two can move on together.
It's very clever as much as it's careful in training the player one concept at a time. Eventually, enemies appear that may be destroyed only on one side, but give up their collectible points on the other side, meaning you have to run through the level with characters on both sides. Another set of puzzles involves a yellow panel in the ground that when jumped or landed on by a player on one side, sends the player standing on the other side into the air in the opposite direction.
When two players are working in tandem, this game is totally awesome. However, there's nothing quite as frustrating as when the other guy you're playing with just doesn't seem to understand his role in the puzzle. This is accentuated by the fact that when one character dies, the other explodes in a puff of particles seconds later, and both are sent back to the last checkpoint together.
Still, what I played of Ibb and Obb is an enjoyable game that's sure to be fantastic fun for players who enjoy exploring puzzles together, like in Portal 2's cooperative mode. If you, or a friend, like to hang out on the couch and give advice on a puzzle another friend is working on in a new game, then Ibb and Obb is for you. I laughed hard and shared smiles with strangers after we figured out a particularly tricky puzzle. A game that unites people in purpose—that's a very cool thing.