Ok:
It looks ugly. The font is bad, and the general layout doesn't look good.
The controls are finicky, I don't like them, the joystick is too close to the center of the screen, and the method of firing is very very annoying.
The instructions are not complete, if I did not know how you were supposed to play the game, I would be annoyed and probably exit and delete.
The high-scores screen should have a link to it on the main screen.
There is no apparent method of exiting the high-scores screen.
-Mist