Just a quick insert, Modern Warfare 2 ROCKS!!! Although I can only experience the multiplayer, I have to say they improved upon everything from the first game. The the gaining of levels now makes a huge difference, as now certain classes can only be unlocked by reaching levels (Although the same gaining levels to gain access to new weapon attachments and I believe new weapons remain) I only got a chance to play 3 games, but I do believe I'll be buying it in the future, and I recommend to you ALL to try it out this weekend. Not only is it free, but if you are planning on picking it up in the future, It's double XP weekend, so you'll gain levels faster! Give it a try, I PROMISE you won't be disappointed!!!