New this release: a new Pathfinding behavior! Here's a quick demo of pathfinding, showing how it can help objects navigate around obstacles.
The Pathfinding behavior divides the whole layout in to a grid, and marks cells as obstacles if they are touching any solids. Then it uses A* to find paths through the grid. You can access the sequence of nodes through the behavior's expressions, or alternatively tell the behavior to move the object along the path for you automatically.
One of the coolest things about this new behavior is it uses Web Workers to run the CPU intensive pathfinding calculations on a separate thread. Pathfinding a lot of objects can take a second or more to calculate, especially on mobile devices, and normally this would make the game hang while the paths are worked out. However with Web Workers the game keeps running smoothly while paths are calculated in the background. On dual-core systems (including phones!) this means a separate CPU core can be used for pathfinding, preventing the intensive calculations having any effect on the game framerate! Web Workers are also supported almost everywhere, except IE9 (IE10 has support) and the Android stock browser (but Chrome and Firefox for Android both have support).
The Pathfinding behavior is similar to Classic's RTS movement, but renamed to indicate it's more general purpose than just for RTS games. C2 improves on the RTS movement on two counts: Classic did not use threads, and performance tests indicate C2's Pathfinding behavior is also 2-3x faster (even in Javascript!) due to algorithmic improvements. However note that because C2's pathfinding is asynchronous, you need to use it a little differently: the Find path action only starts looking for a path, and the result is not immediately available in actions after. You need to wait for the On path found trigger to run before you can access the path or move along it, and it may take a moment to calculate. You should also still avoid unnecessary pathfinding calculations (such as calculating every tick) since this may waste battery and make other paths take longer to calculate since the Web Worker will be constantly busy.
Anyway, it should be a very handy behavior for certain games like turret defences or making smarter enemies which can find you more intelligently. Check out the new Pathfinding example in the Start dialog for a visual demo of how it works, including mapping out the nodes.