Some people have already given their take, so I’ll add to it:
The game has a couple of hours of actual, fun content. After those couple of hours you’ll start to notice that everything is the same. Oh sure, the creatures and plants are made of different parts, but that’s as far as the differences go. Every planet has the exact same pattern, every system has a space station with the exact same functions, so eventually it really feels like exploration doesn’t matter. Which kinda sucks for a game that’s supposed to be about exploration.
I’ve always said that exploration would’ve been far more impactful if the universe of No Man’s Sky had just a bit more realism in it. This would mean most planets would be frozen iceballs or low atmosphere dustballs with no life on them. This would make discovering a planet with life on it quite momentous. It would also eliminate the problem of quickly finding out all life on every planet is exactly the same.