I'm amazed by Fauxton. It's well-written, complete and, most importantly, super cool.
I've been fiddling with it a little bit, I tried to invoke the demons of mathematics but cannot find an elegant solution. I'll keep trying, but maybe it's something that the lib could benefit in some kind of update, it seems to the kind of feature that we expect from a 2.5d lib.
The billboarding (the fact that the player always faces the camera) works fine, but it's still impacted by the "height" of the camera...
Taking the provided example to illustrate, if you move the camera to the very top of your scene, as if you were viewing the scene from the top, the player sprite disappear - of course, he's a 2D flat guy :). Do you have any clue of what to do to make the player fully facing the camera and not being affected by camera's position?
Again, congrats for your work!