A simple physics engine would make it easier to make fancy animations. How to integrate it with the scenegraph is a bit of a mystery.

CanvasNode#usePhysics, maybe.

Could start with a crap particle dynamics sim and go to rigid-body sim from there. Or maybe there is a library for this and we could use that.

Integrates with the collision detection stuff.

Silly, I've recently started a very similiar project with the same name... ;)

I don't know your syntax, but I wanted to do something like applying properties to groups, e.g.

var phys = new Physics(); phys.addForce('gravity', [0, 5]);

var g = new Group([someRect, anotherRect, other, rects]); g.apply(phys);

Maybe I'm wrong, correct me if you can.

http://box2d-js.sourceforge.net/

Integrating that might be a good start :)