There have been plenty of games that feature both playground physics and destructible environments. The awful Fracture and the lovely LittleBigPlanet come to mind. Tiny & Big, though, is taking both features to a whole new level.
An episodic game for the PC, the first instalment is called Grandpa's Leftovers. The game is a platformer that has you moving around and solving puzzles using two items: a grappling hook, controlled by the left mouse button, and a laser beam, controlled using the right mouse button.
As you can see in the clip below, what you can do to a level with just these two tools looks incredible. You'll be able to play a demo of the game next week, available on its website (or, if you want to play it now, grab a "beta" demo!).