Increased Damage
Open your CTU: Marine Sharpshooter directory and locate the file named "autoexec.cfg." Make a backup copy of this file, and then open the original file using a text editor like WordPad or NotePad. Look for the parameter labeled "AITakeDamage." The default setting for this parameter is "0," but you can change it to "2" in order to drastically increase the amount of damage your computer opponents take. Once you have made the change, save the file and exit before starting your next "CTU: Marine Sharpshooter" game.
Walk Through Walls
One of the best ways to achieve one-hit kills is to position yourself in a place that your enemies will have a hard time reaching, but also offers a good vantage point so you can see them coming. Having the ability to walk through walls makes getting to these locations much easier. You will need to edit "autoexec.cfg" again, but this time, look for the parameter "PlayerClip." Change this parameter to "1" to walk through walls. Save and exit before starting your game.
Disabling Cheats
If you want to return the game to its default settings, delete your altered version of "autoexec.cfg" and rename your backup copy of this file "autoexec.cfg."
Increased Accuracy Tips
You can boost your accuracy by firing your rifle when lying down (the prone position), or when crouching. These positions decrease the speed of your movements, but the accuracy bonuses make up the difference. You should never attempt to fire your rifle when standing upright. If you find yourself in the open and under fire, either drop down into a prone or crouched stance and eliminate the threat, or switch to your pistol. The pistol's accuracy is unaffected by your stance, making it ideal for close-quarters combat situations and shooting on the move.