This is Counter-Strike 1.6 running just fine on a mobile telephone. Servers and everything.
Is it the ideal way to play the game? No. But it’s a lot more practical than folks trying to get Doom running on calculators and ATMs.
The touch controls look like a pain, but this being Android, it’s not going to be hard hooking proper peripherals up to your tablet/phone if you need more precision.
Note that this is actual CS 1.6. Not a recreation, not a stream, but the game itself running on the mobile OS.
If you want to try it out, you’ll need 1.6 in your Steam account for some of the necessary files.