Giant Bomb reports:
''Mercs 2 feels like it was built to play with a partner right from the get-go. As you're starting a game, you'll be able to choose if you want to make your session totally public, limited to your friends, or locked down to invite-only. This means that players can jump into your game at any time, depending on how you set it up. They'll also be able to jump out without disrupting your game or forcing you to quit back to some single-player version of the game. After seeing it in action, it definitely seems smooth--certainly smoother than most of the other games that have attempted to offer this style of easy-to-access co-op, anyway.
So what will you be doing when playing with a partner? Blowing up twice as much stuff, naturally. I played through a couple of missions that gave me and my Pandemic-based partner plenty of opportunities to destroy things, as well as opportunities to acquire more gear and munitions. The first mission had us sneaking onto an island by boat and calling in our chopper pilot to airlift some missiles out so we could use them to blow things up later. This mission mostly had us worrying about ground troops. The gun mechanics felt a little like Call of Duty 4 in that the left trigger lets you aim and snap to your target, making even long-distance shots fairly routine.''