is there any reason why you don't patch this game ? I don't think changing the size of buttens is really a hard work. Seriously, if the cobtrol pad wasn't that big, i would have bought no ads version because everything else are perfect.
The scale of the buttons is calculated based on the screen density as reported by the device. I have tested this calculation on several devices running both Android and iOS, including several iPhone and iPad versions to make sure the buttons are the correct sizes for any screen. However, sometimes the dpi value is not accurate and it's possible that on some devices the buttons are too large or too small for the screen. You are the first to mention this issue, and I am looking into fixing it, but it may take some time because I am also already in the process of adding some new features to the game which are not quite done yet. I do hope to have a new version out soon, so please be patient. Thanks for your feedback and your interest in the game.
the best way is to give the players an option to resize the control pad so they can choose the equal size for each device.
Also it's nice to hear that you are adding new features.
Some new enemies like hexagons from asteroids deluxe would be good. But if you are about to add hexagons, you have to tweak the contols too, because the control of this game is quite slow like asteroids than fast and stable like asteroids deluxe or space duel.