Every FPS that was not made by valve pretty much follows the path paved by Counter-Strike.
Gameplay: 9/10
You get to play as either the counter-terrorist unit or the Terrorist unit. You get to pick the avatar you want for each team and then the fun begins! You get to play standard maps like de_dust and then ranging up to custom made maps made from fans. After playing this game for like 6 years, I haven't noticed too many flaws except fake physics. What i mean is the unmoving sniper rifle scope that moves when you use a similar weapon in COD. Another flaw is the fact you can get walled. Shot through the wall, Yes. There are a good amount of weapons. Some like the m4, ak47, mac10. If you're interested in Grenade Launchers and missiles, than this game is lacking in that department. Why would you want those anyway? You want people to know you are skilled enough to screw them over without all the explosives.
Story: 0/10
No story. But who cares? Its an online shooter which lacked a story. So whats really the story? Kill the terrorists or Counter-Terrorists.
Soundtrack:0/10
What soundtrack? The sound of bullets! and perhaps people dying and so forth.
Interface:9/10
Steam really does a good job integrating this with their system. I played this before they actually had steam which was totally different. You basically just had to log in with your key and play with others. Easy and not hard. Dedicated servers were the best since they reduced lag and so forth. The worst thing in CS are probably the hackers. Steam does a good job banning these a$$holes out for a year, so i can't complain.
Despite having 2 zero scores, this game still gets a 9.0. Why you ask? Story and soundtrack would have actually made this game worse. It is fine the way it is. One of the best online shooters and best shooters.