You've made a great start, must have taken a while to implement everything you have. May I ask how you coded the physics object movement (to move at the centre of the camera screen)?
I use an old newton dll. Similar code in the "newton game dynamics tutorials." http://www.coniserver.net/down/setupngd.exe "\Newton\newtonTutorials\pool\newton_physics.wdl" "gravitation_gun" function.
