There are a few good mobile FPS + open-world style games right now. Games like PUBG Mobile give a large open map with shooting and survival, while titles like Gangster Vegas mix open-world exploration with shooting elements similar to GTA.
But honestly, true open-world FPS on mobile is still limited, most games are either battle royale or sandbox-style.
If you want something smooth and fun, GTA SA apk still runs really well on mobile and gives a proper open-world experience with good performance (even feels high FPS on decent phones).
