ummmm plz enable the sliding joints to start open. and allow the option to choose what collides with what. (e.g. ball collides with triangle, triangle does not colide with square, square collides with ball) oh, and allow the density to be 0 =D (floating object) and allow a option to make the object breakable, and how much force b4 it breaks.
hmmm... you should and the sun, change the cycles to days, and put animals in the background maybe? add acheivements and seasons and make random events (e.g. flying saucer at night, elclipse in the day, etc.) and maybe allow upgrades (suggestion: binoculars, allows to see whats happening on the moon. If you use it at the sun, the screen will turn white and black for a while as if blinded) allow areoplanes and stuff to fly about in the sky =D maybe some text? Maybe add acheivements or something.... and most of all, kongregate API. =D