In addition to working on Canabalt, we've been tinkering the last few months with a 2D physics-based puzzle game. After a bunch of waffling we've got a name, finally, and thus a logo:
The objective is simple, get an object from point A to point B. Each level has a number of physics elements in it, which you can erase, or activate, or pin. Pinning an object allows it to swivel on that point, which allows you to build simple machines causing your object to roll or fall or be thrown or what have you. Get your object to the destination, and ideally do it in an optimal number of moves.
I'll make a few more posts with example levels as we move forward on making this something actually shippable!