Meh, too repetetive. gets boring after 10mins
What do you want there to be? A storyline? Be able to buy new weapons and armor? Seriously its a game that you're supposed to play online and replay, just like the L4D series.
Also the first time I got it, I couldn't stop. And Im not kidding I'd come back home and then I play tf2, eat supper, play it again till 11PM then go to bed. Im not as addicted to it because of all the new games I got but I play at least 4 times a week still.