We haven't heard anything about Ibb and Obb since Indicade in 2008, but we're so, so glad to be reminded by this video.
Now due to premiere on PlayStation Network this year (with a PC release to follow), Ibb and Obb is a co-op platformer that presents two worlds with opposite gravity on either side of a line, both full of geometric shapes and contrasting color gradients. In other words, the middle of the screen is the ground, and gravity is opposite on both sides. Just ... watch the video.
Ibb and Obb is designed to be played by two, with local co-op built in. According to a YouTube comment by developer Sparpweed, "We want to patch online co-op as soon as we're ready with that."