How About Critical Ops On Unreal Engine 4. It is a great engine and it also easy to develop. It supports many modern features and utilities for developers to make a game easier to develop. and the most important thing it supports a wide range of mobile device and it also very stable. and it will also fix lag we are currently facing. we have many great examples such as PUBG Mobile, Fortnite, Vainglory etc https://www.androidauthority.com/unity-vs-unreal-engine-android-game-development-842045/ Vote for your choice