Multiball Pinball (US$2.99 for devices using iPhone OS 2.2 or better), is billed by Matmi, publisher of three other pinball games, as their most extreme pinball yet. If extreme, means busy, chaotic and possibly headache inducing, I'd agree with them.
Let's try a test. Look at the graphic on the right for a few seconds and try to figure out what's going on. This is a one table pinball game with no close-ups or camera movements to direct your eyes such as found in Wild West Pinball, a cheaper, and more nicely designed app. You can see that the screen is very busy, and seems to use every pinball component possible. But being the most feature laden pinball game out there is not necessarily a good thing. There are four flippers controlled by tapping on the left or right side of the screen, but one flipper is often obscured by overlay text, like the one under the big X BALL display.
The app does come with a few pages of instructions, in type a bit too small to easily read, and any direction is quite useful, but what isn't welcome is the total chaos of gameplay. As I played, I found the right flippers have a hard time bouncing a ball to the top of the table since the path is obscured by objects. There is always a lot going on, like ramps, cannons and smoke, but their design leaves a lot to be desired. It's not very clear when a ball enters a ramp, exactly where it will come out. When a smoke effect appears, it often obscures your view of the ball.