I very, very nearly pre-ordered No Man's Sky, and seeing how well it's run on most peoples' systems makes me very glad I didn't, plus from what I've seen even if it DOES run, you'll have seen the entirety of what the game has to offer in two hours.
Pretty sad that eight years later we've got a game that fails nearly the exact same way Spore did, whilst attempting to do (to some degree) the exact same things Spore did as well. It's like this specific niche genre has a curse or something. IIRC this is the second major game to try this sort of thing, maybe the third time will be the charm? Hopefully?