We looked at these several years ago when I was working for a poker machine manufacturer. There is a whole lot of legislation to do with electronic gambling machines here in Australia, I think we have some of the strictest regulations anywhere. As such, games of *skill* are not legal, which is to say the user input can have absolutely no bearing on the outcome of the game. In a pachinko appplication, the user input decides only the pin on which the first bounce occurs, and the game takes over from there. It's fairly easy to set up scripted 'bounce' animaton parameters that look dynamic. Once you pre-determine the series of pins that the ball will traverse, you reverse engineer parabolas that force the point of impact on each pin to one side or the other to provide a natural looking bounce towards the next pin.

Sadly, I left the company while those machines were still in development, and haven't seen them in general release, so I can't really comment on their commercial success or otherwise. But as you said Razor, they're for the Japanese market.

On another note, if you've ever played on of the physical pachinko machines... you'd be pretty hard pressed to make anything so loud and garish in flash.