Hmm, fair question. My last playthrough has been a while ago - so I'm not entirely sure I've seen all there is to see. I distinctly remember exhausting the Village story arc and exploring the actual planet as much as I could. I think I hit a black wall then.
I like the exposition approach to it all: You start on a rather linear path, get to know all the intricacies of the overall story (but not too much fluff) - and then are catapulted into "the situation at hand". Although there is not THAT much content, the entire sandbox experience is exactly what I want from games like this. You can explore on your own, manage some gear, cultivate little story arcs (or not) and have generally some "fun" scientific discoveries. The implication to build (or avoid) "contamination/corruption/lewdness" is the key here - it implies further darker or lighter paths ahead. Plus the Village mystery box (and it's larger story).
Then there is the easy navigation (inside the ship) - what a nice hub for activities! In order to shorten this: You have certain game UI elements and design choices that are very nice and mature. The design is ambitious (even the story structure and where it leads), it must be rather hard to stick to the overall higher production quality. Which is my key issue with the game: You decided to switch the engine mid-game development. This has to be a rather hard uphill battle for you, maintaining both branches (effectively two games) AND developing each story content.
So these are my two cents from the top of my head. I'm intrigued, the story and design both lead you to expect a game I'm deeply rooting for. Cuz y'know, the "Anomaly Vaults" (NoodleJacuzzi's work) of this world are super fun and nice - but the story-heavy games are where this genre truly shines, for me at least. Hope this helps in any way. Take care and have a great week!