Alright, you're required to change up your weapon between the three different types. If you don't, your shot runs out and you're stuck with pretty much nothing (it's a weapon, but VERY weak... Not even worth having). This is fine. The problem is... Whenever you touch the weapon change button, the game can't read the multiple inputs correctly, and your ship will either jump to directly under the weapon button, or to the top left of the screen.
There's no way this was playtested. I've tried on both my iPad 2 and iPhone 5... Both with the same results. It's a bit ridiculous that this was released with this HUGE game breaking issue still in the game.