Man o man this is an excellent game. This is thee best first person shooter i have ever played. Most first person shooters don't really have a plot its just shoot everything around and don't think twice about it. In half life there is a deep and interesting plot. Its still shoot everything in site but it has a plot and that's important. It is also nice to be able to use security gaurds and scientists. Ever since i got the game i haven't been able to put it down yet. The add on counterstrike is even more addicting yet. All and all it is a great game and a must have.