Going into the city on a mission, things are soon interrupted for the would be mercs as Shanghai comes under attack by an unknown force known as "The 40th Day". City wide devastation ensues with buildings coming down around them, civilians running for their lives and soldiers storming the streets. This ties directly into the story and gameplay itself. With civilians being gunned down or taken hostage. Optionally through the game, you're actually given some moral flexibility to rescue those caught in the middle as well as how you handle enemy soldiers. You can actually choose to handle some combat scenarios by taking your own hostages and forcing a surrender where you subdue opponents. Of course you can always simply kill your enemies instead (and civilians). We know this will have some impact on the story in the long run, so it'll be something to keep in mind.
While the story of the 40th day itself may seem to be the focus of the game, make no mistake, a large part of the experience is dedicated to the relationship between Salem and Rios themselves and how it will unfold. No details are known at this stage, but it seems that it will also have impact on the co-op interaction as the story unfolds. EA Montreal is planning the game to be a bit longer than the first, so there should be plenty of time for that to happen in the narrative. Using a well timed mix of action, story and humour, the studio is taking great pains to ensure the pacing of the game gives more impact to the player.
The Co-Op gameplay will also change at various times from external forces as well. As the two partners find themselves separated due to the city coming down around them. Sometimes objectives will differ, or you'll need to co-ordinate fights with more planning involved. One scenario saw Salam get ambushed by some 40th day soldiers. He used their surprise at seeing an armed merc to falsely surrender (which allows him to take full "aggro"), all the while Rios (whos view you can see in a mini-cam in the corner of your screen) lines up a headshot from a distance. In a timed move, Rios took the shot while Salem used that moment of confusion to pull out his pistol and run for cover, leaving the remaining 40th day soldiers confused and scrambling. This being only one example of the array of tactics found in the "Playbook".
The partner AI also does an excellent job in game if no one is available for co-op at the moment. Essentially anything you can do in game, you can instruct your partner to do using a combination of the d-pad controls and the "Playbook" tactics. It worked quite effectively and there didn't seem to be any hitches.
Lastly, the humor found in the original title is still going to be present, but better defined. Since the environment of a Shanghai under siege leaves little room for the over the top humour of the original, expect a more subtle dark humor that fits the context of the situation, while still leaving a smile on your face.
Some final things to keep in mind, there's a new trailer for the game being shown on GTTV with Geoff Keighley on April 30th that you won't want to miss. As well, if you haven't already, give the first Army of Two a try. You'll be in for nice treat when you fire up 40th Day and it sees your save file from the first game...
Keep your eyes on Co-Optimus as we'll have continuing coverage and details for Army Of Two: The 40th Day.