Ok I see. So basically two more biomes with bosses in order to complete the overall vision, and then more content from there.

Did they actually say full release was years off?

It's really hard to know when to jump into a game with these long early access developments, if you want to experience the developers vision of what the experience should be. I guess some don't really have one and more or less make it up as they go. I'd prefer to have some clear signal from the devs that that everything there is working as intended. That's what a 1.0 release normally does atleast.