The Id Software classic on your Android
This version of the game allows you to choose between three different types of controls. Depending on your preference, you can control your viewpoint using your device's accelerometer, or use touchscreen controls for everything.
With regard to everything else, Quake 2 for Android is exactly the same game that you've always enjoyed on your PC. Same levels, same enemies, same weapons - everything together again, just on your smartphone's smaller screen.
The Quake 2 application that you download doesn't involve the game's additional files (another 40 mb), so you'll need to download them later from within the application. So basically, everything you need to play is in the same app.
Quake 2 is an outstanding FPS action game that has only one problem on Android - its control system, which could use some improvement.