Story mode is fun, but the fun realy starts when you play online.
Once you get through the story mode, you unlock the Zombie mode. Zombies come at you in waves, and based on the number of zombies you kill, you can get weapons and ammo. It is really fun, and great to play with friends and family. Once you start playing, you really can't stop.
Online play is pretty darn good. Without a mic, you may get a little angry listening to people that you cant tell things to, but the play is great. Also, there is little to no lagging at all if you have a good connection, and most of the people online are willing to help you start out if you are just begining. If you have a usb logitec mic, or PS3 mic, you are set to go. One of the most addicting gaming experiances I have found so far.
Overall this game has yet to dissapoint me. Garrunteed to fulfill your FPS needs. Buy it, keep it, play it over and over and over again.