GameSpot writes: "The Zone isn't a friendly place, and if you played last year's shooter/horror/role-playing hybrid S.T.A.L.K.E.R.: Shadow of Chernobyl, this comes as no shock. Clear Sky offers a few improvements and a number of issues, but the real star of the series--the large, barren wasteland created by a fictional explosion of the infamous nuclear facility in Chernobyl, Ukraine--is still the most impressive aspect of this prequel. This isn't a full-fledged follow-up, but rather a stand-alone expansion set before the events of the original. You're introduced to a new main character and several new mechanics, the most important of which is factional gameplay, which allows you to ally with an AI-controlled group and assault its enemies. Unfortunately, new features come with a price: new bugs, erratic difficulty, and other annoyances further disrupt the immersion. While Clear Sky is a good game, it's disappointing that developer GSC Game World failed to address the problems with Shadow of Chernobyl that were left to the modding community to clean up."
* Amazing, oppressive atmosphere
* Enemy stalker AI is often remarkable
* Huge, chilling world to explore
* Faction war gameplay adds focus and replay value
* High level of difficulty won't be for everybody
* Bugs, bugs, bugs
* A number of small frustrations