From initial looking at the game, and the description, it very much looks like a game that I would want and buy right away (funnily enough Steam thinks so too as it was high in their recommended games for me) however the second I look at the price and see its $20 (USD) in early access... that stalls my excitement. I mean, it just dropped in early access, which usually means it still has a ways to go before it is fully completed.
While it does look beautiful at the start, and definitely there seems to be a lot more that will come for it, there doesn't seem to be a lot of substance or story to the game yet, it mostly just seems like exploring for resources to survive right now, and uncovering a "mystery" which could be anything really... I know that will come with more development, but I have an expectation of a more complete product if I'm going to be paying the same amount that I could pay for a more complete early access game that is further along in development, if not close to release (i.e. The Forest, Rust, DayZ). Not to mention that there are many games already complete on Steam that go for that amount, or close to it.
I also feel hesitation because at this early stage on a game the developer could still drop it and move onto some other project and put this on the backburner.. Its happened on a few other early access games where the developer is successful in their early access, make many sales, and they suddenly don't seem as motivated to continue updating and completing the project as quickly as when they started (Brings to mind Starbound for me right now..). Not that all developers will do that, but there are a few.
Honestly, I will be keeping an eye on this game and how it develops, because as I said it does have potential. Add a few more unique and interesting game play elements to make this title stand out and I will happily pay for it in Early Access.. but right now I would be cautious about it.