I again revert back to my original question - why the hell does this renpy software need access to 'all' my files and even the power to modify them.
You probably dont install Apps from different sources often.
As far as I am aware the problem comes from the fact, that Application on mobile phone cant just request access to read "some limited" files (in one specific directory). Either it has access to (all) files on storage device or it doesnt.
Same with ability to modify files. You cant give it ability to modify just some files (in one specific folder). You either allow it to modify files on storage device or you dont.
BTW: Surveys from Security companies show that almost 3 out of 4 apps ask for access to storage device (and ability to modify files). Those Apps usually need it to function correctly. Basically it is pretty common.
As for your security concerns: Access to your files doesnt make you particularly vulnerable. Why? Because access to files doesnt allow App to send your files somewhere on the internet. It is entirely different category.
As long as you
dont give the App
"Full Network Access" (or something like
"Wi-Fi Access") then it cant send any data away.
Only if App asks for both Network Access and Access to Storage Device you should be worried.