I see nothing wrong here. The game’s native aspect ratio is 16:9, and you can either view it at that ratio (letterboxed), or turn off letterbox and stretch it.
What you are probably referring to is taking up the full screen without stretching, which (as explained elsewhere) is simply not possible because it would change the layout of the waves (amongst other things).
There are already several instances of Android players who have tried to subvert/circumvent Google’s in-app payment system and pretend that they have paid whereas in fact they have not.
Because the computer version won’t work with Google’s AD system. Have you seen a single PC game that has Google AD? Excluding the madness of Windows Store, these are technically mobile games.
It’s easy to edit the inapp libraries in any app to emulate or bypass the purchases (lucky patcher / editing the library itself with some RV experience)
So redirects payment to PayPal is more save option