~12 hour campaign that can be played co-op with up to 4 players. Decent length for a FPS made extra spicey with the 4-player online co-op.
Multiplayer extends the enjoyment though there will be some who will jump straight to the multiplayer and ignore the campaign altogether.
What I really meant was I doubt the story will be one that keeps you more engaged than multiplayer.
Something probably like.
Go from here to here.
Go from here to collect this with the help of this person.
Take the thing to this place with said person.
Said person betrays you and now you have to retrieve the thing.
Everything is about to die, reach the place to retrieve the thing and leave.
*** Ending must leave user unfulfilled, so we can make a sequel. ***
^ That's probably not really the story, just making a point that the single player will be pretty straight forward and offer no deep real plot.