There are many mobile action games available in the form of APK files that you can download and install on your Android device. Some popular examples include:

PUBG Mobile: A battle royale game where players fight to be the last one standing on an island.
Call of Duty: Mobile: A first-person shooter game set in the Call of Duty universe.
Fortnite: A battle royale game with a focus on building structures.
Assassin’s Creed: Rebellion: A strategy game set in the Assassin’s Creed universe.
Shadowgun Legends: A first-person shooter game set in a futuristic world.
To install an APK file on your Android device, you will need to enable the option to install apps from unknown sources in your device’s settings. Then, you can download the APK file to your device and use a file manager app to open it and install it.