Looks like Christmas came early this year :) I love the border you made!
A note on the graphics: I like the static bodies in test 3, the stars from the collision filtering (they look like a pufferfish) and the border around the screen. The rest looks a little weird, but that might just be me and my no sense of style. I can be
The Agent should have a custom made texture - it could be a little like it is now, but with dark gray in the circles and lighter gray for the bars.
A note on the optional parameters: I've had some users complain about my usage of optional parameters, so I reverted the code back to using overloaders instead. It is not really a problem as I can quickly refactor them to overloaded methods using a script.