I added Estranged on Steam's Greenlight Concepts site as an experiment to gauge how interested people would be in this being on Steam, and the response has been overwhelmingly positive.
So, when I the next update I will be adding it to the main Steam Greenlight website, with the aim of releasing it on Steam when it's finished.
Speaking of Alpha 5, that should land sometime after Christmas. I've already completed another map, but progress is slow as I'm fitting this around a full time job. I do have a couple of weeks off around Christmas though, so a lot should get done then.
I'd like to thank everyone that has supported the development so far, and hopefully we can follow the future of Estranged together.