This game is a great First Person Shooter (FPS), especially if you´re thinking of playing with your friends!
The things I liked most about this game is how fast you lose track of time when ur having a blast online shooting enemies who might turn out to be a friend in the distant future, I´ve met loads of friendly people just by playing the public section of the game!
The way you play the game is basic and simple, two teams compete against eachother consisting (most of the time anyways..) of a balanced team with an equal amount of players in both teams.
The two teams are Terrorists a.k.a. T and Counter-Terrorists a.k.a. CT, where the T side has to either plant a bomb at a designated place or guard the hostages on certain locations, and the CT side has to protect the bombsites or retrieve the hostages to a capturezone to eventually win the round.
Back in my day the game was mostly competitive, now all that´s left is public servers which still offer a good variety of skill levels of players and loads of custom maps so this game is really worth it´s money.
I alone have played this game for more then 2000hrs which gets back to my previous comment for how easily it is to lose track of time.
DEFINITELY A MUST-BUY!