Online co-op game Gunshine.net is out of beta after months of testing from users. The four player game ties into Facebook and offers a slick RPG/Action experience that's a bit like a modern day remake of Syndicate - no... not that Syndicate.
Obviously, being a Facebook game, the entire thing is free with supported microtransactions. I've personally been playing the game since beta and it's come a long way. You'll start by creating a character and working your way through a brief tutorial, then you can invite some Facebook friends to take on co-op missions and bosses, earning experience, and leveling up your custom character.
Here's a video of the game in action.
As you can see, this isn't just a simple Facebook game, but a fully 3D multiplayer experience loadedo n demand in your web browser. It's pretty impressive. You can sign up for Gunshine.net for free at the official site.