Packaging and Google Play [Need help soon]

I’m finally done with with my android app. I managed to sign and package my game into an apk. The game ended up on 250MB!
1: Does anyone know an effective way to shrink the size of my game?
2: Google Play only accept games when they’re under 50MB unless you have an apk extention. Let’s say I doesn’t achieve to get my game under 50MB, what do I do? I’ve red somthing about .obb files and maybe that’s an option? I’d really appreciate an answer!