CS for the dial-up'er or Internet-less player
Condition Zero is essentially CS offline. Containted within the game is the "Tour of Duty", a collection of classic and new CS maps with certain objectives and challenges to complete such as:
Win in under 75 sec.
Kill 5 enemies
Kill someone with (weapon here)
get ()WN3d (Jk)
this allows a challenge to players who are experienced and allows noobs to learn the basics of counterstrike and familiarize themselves with the weapons, maps and equipment of CS. The difficulty rating you pick changes the number of challenges and difficulty of the bots. As you complete maps, you unlock "Reputation points" you can use to assemble a team of CT's.
Condition Zero's other SP experience is Deleted Scenes. These missions are a series of story driven missions that are typical of traditional FPS games. Most of these missions are easily completeable in less than 20 minutes.
CZ also gives CS a facelift, redoing textures and models to at least a more acceptable standard. New quipment both online and offline also adds to its replayability. All in all, Condition Zero is an excellent place to start for people getting into Counterstrike and a perfect addition for CS fans, costing about $20 or less