Here’s an early screenshot of the physics editor in action.  The Cuttlefish Engine allows you to set up physics objects, place them in your map and control them via script, paving the way for all sorts of crazy physics-based gameplay.  And of course you can instantly preview your physics sim (in the screenshot, see the preview button up top? Click that and it’ll play in the phone on the right).

The physics editor of the Cuttlefish Designer.