Its a fantastic core gameplay loop however the save system and progression system sucks ass for most people. I gave up after biome 2, dont have hours at a time to play unfortunately with a family.
That's where I ended up and my ultimate thoughts. And I don't even have a family yet, just a fiance, and even that prevents me from being able to endure a four or five hour single-siting run or try to rely on sleep mode to same my progress (which failed me as, in this heat wave, brownouts or random but brief losses of power are more common).
I don't see what's so hard or controversial about adding a save. I mean I could spit ball it but I'm no game designer: one finishes a biome and they save - done. I had to really give some thought to that one but I think it could work.