I play it quite a bit, in fact I am a member of an all veteran squad. It is very team based and all fighting is done online, no missions (besides basic training) are done solo.
If you are a CS player, give up all hope. No rambo and bunny-hopping in this game, and you WILL get booted from the server for shooting your own players, no questions asked. The server keeps track of you hurting/killing squad members so if you do too much damage to your teammate, you will find yourself out of the game.
It is pretty good so far, they have only released some of the game so far, the rest is to come.