the author of this app says:
The game features a horde of alien ships swooping down on the player who is defending the planet.
The player's rocket can be controlled by tilting the device left or right or by tapping on the sides of the screen.
- three levels of difficulty
- automatic or manual shooting
- high score table for each level or difficulty
As the difficulty and levels increase, there will be more and more aliens attacking the player.
What's New in version 1.2
- New UI
- Grabbing (tapping on the rocket) and swiping the rocket moves it (or with the accelerometer)
- If autofire is off, tapping on the rocket fires
- Smoother gameplay
- Using iOS 4.1
- Requires iOS 4.1 or later.