It's playable, but you'll get to a point and you can't progress any further. There's been no game update for a while now, and despite a few tweets here and there the community feels there's been little to no feedback and they're quite irate.
The forums over on Steam are awash with disgruntled folk, but the last update says it'll be a while as they're redesigning fundamental mechanics of the game.
I enjoyed what I played, but I'm a bit cheesed that nothing has happened for a while. Personally I'd hold out for a bit knowing what I know now.