Mercenaries Salem and Rios are back in another testosterone-filled, action-packed adventure in Army of Two: The 40th Day. This time the former Army Rangers are now the heads of their own private military company, TransWorld Operations (T.W.O.).

They've been hired for a deceptively simple job: run around Shanghai, plant a few mysterious devices and take out any opposition. But as the city literally begins to explode around them, they quickly learn that there's more going on here.

Unlike the first game, there isn't much story to be found here. Most of the game is spent trying to stay alive and even by the end, not much is revealed. However, Rios and Salem become much more personable this time as they frequently will remove their masks when not in combat. Salem lightens things up as well with plenty of sarcastic comments throughout the two's escape.  The over-the-top wildness of the first game has been toned down quite a bit, in favor of a more serious tone. Unlike its predecessor, The 40th Day introduces tough moral choices.  Players are forced to decide: Betray an ally for a bigger pay check, or let him go? Save the hostages or just blow everything up? The game stresses the impact of your decisions by showing the long-term consequences of your actions and by giving rewards or punishing you.

Like the first game, The 40th Day is meant to be a co-op foray. While the partner A.I. has been improved, it still can't compare to working alongside another person.  The "aggro" system is back and improved. Both Rios and Salem are equipped with GPS units in their masks which allow them to tag enemies.  The popular weapon customization system makes a comeback, this time with even more options. You can mix and match between just about any weapon part and there are plenty of jury-rigged pieces you can use, such as a screwdriver bayonet.  In addition to getting your gun gold-plated, you can now also choose from several different paint schemes which can raise and lower the weapon's "aggro" level.

For those who like challenges, the enemy A.I. has improved. Enemies are now able to perform all the same co-op actions as Rios and Salem. If an enemy falls, but isn't finished off, another will try to revive them. They can hoist each other over walls, or even take your partner hostage.

The 40th Day has gotten some hefty graphical upgrades as well. Salem and Rios are far more detailed, revealing tattoos and scars. Shanghai is presented vividly and there are some awe-inspiring moments as the city falls apart around you.  During one particular skirmish in a skyscraper, a plane crashed into the building, shearing off everything overhead and taking with it everything that wasn't nailed down.

The game's replay value is in the difficult quests to unlock new customization options.

From the complex tactical options in combat to the difficult moral choices the game forces on the player -- not to mention the and the new-and-improved enemy types -- Army of Two: The 40th Day makes for a very fun co-op experience.

Final Score: 7/10