I have recently played the Pool.app (best game!!) I was thinking... Pool has all the object collision down quite well + descent aiming (for us narrowly shaped fingered individuals) and a power adjustment tool.
Somehow i suppose this could easily be implemented into a Bowling game. A very simple one... with no spin, gutter,score or such... till later releases Obviuosly there are a few basic differences between the games but Pool.app seems to cover the basics.
Tell me if im way off. But i think the possability is there.