I can’t say for sure, but this port of a popular independent shooting game could be the result of the recent release of the iPhone SDK. Kenta Cho is reasonably well known in the circles of indie gaming shooter community and his awesome Noiz2sa game is now available for the Apple iPhone.
As you can see in the video embedded below, controls are completely mapped to the touchscreen display. It seems like your little spaceship shoots its cannons continuously and all you have to do is navigate the ship around on the stage, dodging bullets and avoiding enemy polygons. Gameplay is similar to the Raiden series that you may have played in the arcades.
On a side note, doesn’t this stage look a little difficult for newbies? Maybe there’s a lower difficulty setting somewhere.