Be aware it is an alpha version. However it gives an idea of what they're working on.
I'm sure they're doing their best to get the game ready, but don't hold your breath on the release date. Like just about every other game, the original release date came and went.
No an alpha version is not complete at all. It may contain bugs. It may not play as smoothly as the final product. But the demo would give you an idea what type of gameplay to expect.