https://www.makeuseof.com/make-android-game-friendly/ you could try this for the fps problems! to unlock the prvious date you could always use cheats to unlock the things you have already unlocked.
I tried this & that fixed the FPS problem, but it still won't actually let me play Act 2. I'm just gonna fully uninstall & reinstall it.
Sorry it didn't fix the Act 2 problem, hopefully installing it again will solve your problem!
