Sorry to say but this conversion is complete crap.
There is no way to control the ship. You are apparently supposed to tilt the device to move; however this doesn't work at all (sometimes screen will rotate by 90 degrees is the only effect).
Tapping or sliding the screen also doesn't work properly (ship moves seemingly at random).
So the game is completely unplayable. Obviously it needs further testing and bug fixing by the developers before release. Avoid.
Err, the movement is relative to your finger position... The whole screen works like a touch pad, it felt very natural for me... Perhaps you were expecting something different?
-edit- I have controls x2 on, which works best for me!