Call of Duty: Modern Warfare 2 is the first Call of Duty series that I play. Are you serious? Yeah… Just started to have desktop last year after using laptop for last 8 years. How can I survive without playing 3D games all these years? WOW…
Guess what? Almost 4 millions YouTube views in 10 days. Based on the view rate, this game should a great hit. However, there is no free lunch. You need pay a little more for Call of Duty: Modern Warfare 2 @ USD 59.99. So what are you waiting for, download Call of Duty: Modern Warfare 2 at Steam right now. You need to pay for it of course. 
