Which Counter-Strike game was released in 2004 as a standalone title built around the original mod and new single-player content?

Counter-Strike: Condition Zero was released in 2004 as a standalone Counter-Strike game with new single-player content.

Condition Zero expanded the multiplayer formula with a substantial single-player component. Its Deleted Scenes campaign presented scripted missions, while the game also included bot-supported multiplayer and updated versions of classic Counter-Strike gameplay.

Development passed through several studios before the final release. Gearbox Software initially worked on the project, while Ritual Entertainment developed the Deleted Scenes portion and Turtle Rock Studios contributed to the final version. Valve published the completed game in March 2004.

Condition Zero is often mixed up with Counter-Strike: Source, which also arrived in 2004 but was built on Valve’s Source engine and substantially revised the game’s technology and presentation. Condition Zero instead remained closely tied to the original Counter-Strike design and GoldSrc-era gameplay.