It's definitely niche. It deviates from the standards of most open world/survival games (it doesn't exactly penalize you for exploring, but the fear of new areas mechanic just adds an extra layer of difficulty that can be bypassed in certain ways and makes survival different from other survival games).
If you don't like games that are open-ended and don't have much direction, this isn't the game for you. This game is meant for people to dive into and experiment for themselves without having someone tell you what and how to do things.
I have sunk so many hours into this game! Since it's just come out its a little buggy at times but the game has been enjoyable despite them. Mostly minor things, and I'm sure the developers who have put lots of clear time and care into this game will touch things up in future patches. It's supposed to be a trilogy, so if you buy this game be prepared to be in it for a long haul.
There are no microtransactions or anything of the sort, everything in the game is accessible for the $40 you spend on it. You don't play until modern humans, just until 2 million bc (around the time of Lucy apparently). I would highly recommend for the unique setting and design! It's meant to mimic the difficulty and slow process of evolution, and it seems to perfectly capture both of those while still being fun.