great game. sound is amazing, crystal clear graphics, great gameplay. the cover system can be flawed at times though.
Some may say that the campaign is too short, but honestly, I thought it was just right. A campaign doesn't need to be 20+ hours when there is so much other stuff you can do in the game. You can play online casually or in ranked matches. You can go through a campaign cooperatively sitting next to your best friend or over Xbox Live with someone you don't know. And thanks to Xbox Live's addicting Achievement system, you want to do everything over and over again.
The one small complaint I have is that the cover system can be flawed sometimes; when you want to take cover, you end up doing a roll. Fortunately this is only a minor, rare flaw and didn't make much of a difference.
No matter how many games you play in a row, it is always satisfying when you blow someone's head off with a shotgun or, of course, use the coveted chainsaw.