The download you see is the demo, the full game is version 15. Which can be accessed by buying it on steam or if you've bought this game before in your purchases. I hope that helps.
Yes, and please do wishlist it if it interests you. Every wishlist counts and feedback on the demo certainly gives the developer some hope. Otherwise, if you weren't an early adopter, you'd have to I think support the patreon to gain access to the latest build. I forgot to check the steam page earlier today which indeed only has the demo since it's not in the Early Access program. I was thinking of another game when I wrote that. My apologies.