Aside: SOME SPOILERS!
I've written about Joris Dormans's Machinations MANY TIMES before; this is me trying to create a Machinations model of the "core" No Man's Sky gameplay. Also, I am a No Man's Sky fanboy; it's a great game and you will not hear any equivocation in this blog post. If you want equivocation, there are a lot of other No Man's Sky takes that you could read.
The point of No Man's Sky, as I see it, is getting lost in a science fictional universe; being distracted by finding something unexpected - a gorgeous vista, a strange beast, evidence of ancient civilization or some mystery. So "core" and "point" are not synonymous. The "core gameplay" is actually the thing that you're supposed to be distracted from; unlike, say Go.
Like Minecraft, the first thing that you can do is punch something, probably a tree. In Minecraft, you get wood. In NMS, you get carbon.
Carbon allows you to recharge your life support system and your mining laser. Anything you can punch, you can burn down with your mining laser, so you will probably never punch anything again. (Note: This aspect is not represented in my little Machinations model.)
With your mining laser, you obtain plutonium; it is very plentiful in the NMS universe, and used to fuel atmospheric jaunts in your spaceship. From the air, you will be able to spot heridium deposits; they're rare enough that it's a bit of a chore to walk to one, but frequent enough that you can expect to find some in less than a minute of looking from the air.
At some point, either before or after jaunting to find Heridium, you will walk around and pick some flowers. There are red, yellow, and blue flowers, but for simplicity I am only modeling the red and yellow flowers.
By combining the resources you get from all of these activities, you can craft warp fuel - again, for simplicity I am leaving out the details of crafting, and warp to another system. Depending on which direction you go, you might eventually "win" via warping.
There's a lot that this model leaves out, but I think it successfully captures something about how the resources and verbs of the game steer the experience of the game, creating a smooth mixture of walking, atmospheric jaunting, and warping, while continuously looking around "for resources".