Idea: button to rotate universe

[forresto]

I've been thinking that device rotation in a sand simulator would be fun, to be able to turn the device and have gravity match the real world.

Arbitrary gravity might be difficult, and people use Sandspiel on devices without rotation APIs, so to solve for part of this we could make a "rotate" button that turns the universe 90° or 180°. Then we could make a working hourglass...