Not possible in the least. Here are reasons that will remove your "leetness" from ignorance.
Pocket Quake 2 runs at 2 FPS on a 206MHz StrongARM, XScale is about 40% slower than that. However, PQ2 doesn't run on PocketPC2002 devices because the operating system restricts the amount of RAM that a single program can allocate to under 22MB's, thus not allowing the game enough memory to run.
The data files for Half-Life are well over 230MBs. With the latest update that number jumps to 500MBs, if not more. On top of that, Counter-Strike is far over 200MB's on it's own. You'd need a 1 gigabyte memory card just to install the game on, only to not have enough memory to allocate to the program, and even if it could it would run at under 1FPS, since Half-Life uses so many particle and lighting effects and very complex models, all of which require a very fast floating-point coprocessor, something which PocketPCs lack.
An even greater problem is that the source code for Half-Life and Counter-Strike is not available. If you want to shell out $500,000 to valve for the source code to HL and Counter-Strike, the most popular games for the computer in a long time and which they're still selling actively and making a large amount of money from, then be our guest. Seeing as how it won't POSSIBLY work IN THE LEAST, then it's your waste. And if you care to argue any of my points then that's your waste as well.
You should have bought a laptop.
