If you haven't been able to get in on the closed Beta, then be sure to check out the open Beta of this MMOFPS game.

http://www.firefallthegame.com/en

The game is entirely Free to Play and sports a massive world to explore and interact with. It supports a massive co-op style of game play and also has PvP features included. There are some competitive aspects that are as yet to be announced, but this game looks promising. The art work of the game, in combination with mechanics, are pretty fun.

That said, this is not a super intuitive game. It will take some figuring out and experimentation. But, this is only the Beta so expect a lot of changes. I know a lot of things changed just between Alpha to this stage.

So register for your free account, download the installer, and get out there fighting the Chosen!