The Sandbox has been doing pretty well for itself since it first released almost... holy cow it's almost been three years. Well anyway, in those three years Pixowl's 'powder' game has been updated to a ridiculous degree - even going so far as to receive controllable characters and new elements that let players design their own games within the game.
And now they're going "back to basics" with The Sandbox 2.
The new sandbox is similar to the original in many respects, but now sports a few noticeable changes. Shadows and lighting are a bit more detailed, the physics have been improved, and the various elements now have honest-to-goodness textures to ogle. Some environmental effects have also been included, such as glowing lava and a slight distortion to objects that are underwater. In addition to all of that, it will display multiple layers (i.e. foreground, background, etc) so that your creations won't always have to stack up on top of each other. If nothing else it's great to be able to drop a person into a world full of trees and actually see them walk in front of the trees rather than over them.
The Sandbox 2 should be out by the end of the year. Although if that seems like too long a wait, you could always head over to the official website to try your hand at the open beta.