Caporegime
The gun stays the same and resets to level one power up each game start and you pick up boosts during the current run to about 8 or 10 I think, you upgrade he base level with stars and then can still get the run boosts as well. Some ships have different guns to start as well. It can be a slog but I find it not too bad and repetitive. I bought on the PC as well, the PC version is better and easier to play.
The hardest part of the IOS version, slightly less so on the iPad is my fingers is touching the plane. My hand is blocking the view. I tried a bluetooth controller but it didn't work.
I also tried loading it in my Retroid Flip, an Andriod gaming device. The buttons on the game pad in the device didn't do anything else. I think the game is touch only with no way to use physical pads and buttons.