Thanks 66 M9. Windstone is in very early alpha and was only made available for public download a few days ago. It will be free for quite a while, a few months at least, but a price will eventually be added to it.
Windstone will be a "pay once, play forever"game.
It would be great to make the game multiplayer or at least duo co-op, but that probably won't happen unless Windstone becomes popular enough to justify the resources it will take to do so.
Thanks for your feedback and I hope you have fun playing. A new update is going live in a few hours that fixes a bunch of current issues which will be posted in the update notes. Much more content will be added in the near future.