If you haven't read Chris's piece on "social survival game" Grimmwood, then I'd recommend doing that now—it piqued my interest, but I unfortunately never got around to trying out the free open beta. I may not get a chance now, because it'll be out for good on Thursday, August 2, publisher Headup Games has announced.
In Grimmwood, you and up to 30 players spawn on a procedurally generated map and have to build a town together. Monsters will attack when the sun goes down, and the waves become more powerful each night. You can explore, gather resources and craft on your own, but as Chris discovered, you end up having to relying on other players to survive.
So it's a good thing the community is so friendly and willing to help out. Chris was admittedly a selfish neighbour, but it didn't stop the townsfolk springing to his aid when he ran out of stamina, which is the limiting resource in nearly every situation.
Early Steam reviews were mixed, with some players complaining of the slow pace—the game proceeds in real-time, so an in-game day is 24 hours long. But developer Big Moustache Games (great name, by the way) has added a Blitz Mode that cuts a day down to 15 minutes. Recent user reviews are very positive.
The free open beta is still running, so give it a try if you think it might be your bag.