Good fun game.
The game is made up of several missions you go on to collect cash. If you have played Crackdown and liked it, then I would say you would like this game. I just played co-op with another friend, and he has played Mercs 1, and he said that Mercs 2 is a lot better.
Do you like to blow things up? Well, this game takes a lighthearted direction and doesn't take itself too seriously. To me this is a good thing. It's just a game after all, and when you've had a long day at work you want a game that is enjoyable. I can see myself having a lot of fun in the future with Mercs 2.
The game could have been more polished. There are some weird glitches you will encounter. For example, me and my friend were trying to take the helicopter back to the headquarters and I only got the option after is dismounted the helicopter and boarded it again. Overall, hopefully those minor issues won't keep me from enjoying this game.