Other games that are several times the size of this game run just fine.
It's a game problem. Not a phone problem. Besides, the phone is just a couple of years old. You shouldn't need NASA technology to run a 2D text game.
You shouldn't even play renpy games in mobile lol
If you believe that, you are 100% clueless about games, considering Android comprises a substantial base of almost any developer.
Just because it works for developers doesn't means that you should play those games in it, they don't run them properly for a reason
Yet other Renpy games that are properly optimized run just fine without issue on both mobile and PC, two things you have suggested nobody use because you think these games cannot run on them.