There's nothing as peaceful as meditating upon a Japanese Rock Garden. Here you can make your own. Rake the gravel and populate the sandbox with rocks and grass. Select graphic from bubble menu in lower left. Move and draw with the mouse button. Use up and down arrows to change size of rocks, rake, smooth, paint, and grass. When placing rocks, press space to choose between types. Use left and right arrows to deform rocks. When painting, press space to change color. Use left and right arrows to change brightness.
It's not exactly a sandbox yet but more things will come.