I've been playing for a couple of hours now and so far I really like the game. The artwork is high quality and the story is unique. The only issue I have is that on android the transitions between scenes seem to be a bit slow, but it's not too bad. Can't wait to see what the game has in store for me. Keep up the good work!
Not a lot I can suggest if it happens in every location. The only thing that really changes in places like the mall are the BG images and updating the location buttons. Neither is heavy enough where it should cause a noticeable hang.
The game is also pretty small so probably isn't a memory issue. Only thing I can think is that renpy and your device are not getting along very well and causing the issue.