Sixteen years ago, you needed a reasonably powerful computer to run Counter-Strike. Now you can play it on a damn smartwatch, although you'll need to bring a pretty lose definition of "play" along for the ride. While it's miraculous that Android Wear is able to run CS at all, the game is far from perfect. It chugs along at about 20fps; there's no online play; and the tiny screen is so littered with controls that the only way you'll be scoring a headshot is by accident. It's more to show that it can be done, rather than to get noscoped from the comfort of your wrist.
That said, Dave Bennett — the mastermind behind this little project — has posted some instructions on his website for getting Team Fortress, Half-Life 2, Super Smash Bros. Melee and, of course, Counter-Strike on more powerful Android devices which have a little more screen real estate.