TL; DR(eview) - Less time spent on crafting a universe that will go mostly undiscovered and more time spent on gameplay elements would have benefited No Man's Sky. There are quintillions of worlds to explore but virtually no reason to do so beyond "because they're there."
If you assumed every single person on the planet bought the game (using a conservative estimate of 7.125 billion people, that still amounts to more than 2.5 billion planets per person. If you bring the player base down to 500 million (which would mean the game outsold every iteration of Tetris combined), that ups the count to 36 trillion planets per person. Much like out own universe, the vast majority of the universe of No Man's Sky will go undiscovered. So why create something so vast?
The predominant answer seems to be in the vein of "because we could." With each and every one of those planets procedurally-generated by doubtlessly impressive mathematical algorithms, it could certainly be argued that mankind could play this game until our own sun burnt out and still not see everything in it. As such, it could very well be the biggest game ever created.
No Man's Sky is a technical feat, to be sure, if not a particularly engaging game.
As I touched on in my first impressions, within a first couple hours of the game, you basically done all there is to do: collect resources; scan the local flora and fauna; repair and upgrade your tool, suit, and ship; occasionally use a bit of your resources to recharge your equipment; shoot at some sentinels or pirates; slowly learn alien languages word by word and interact with them; and fly from planet to planet. And of all of these elements, only the act of "getting in your ship on one planet, flying into orbit, traveling to a distant planet, and landing" makes for a real engaging experience.
All of this occurs without a loading screen, the only "hidden" loading screens really come into play when using your hyperdrive to warp from one system to another where you'll be greeted with a "hyperspace" graphic as (presumably) the solar system generates itself in advance of your arrival. Admittedly, the pop-in is very apparent and abundant as you flight around a planet. Even on foot, there will be a pillar representing a mound of gold from a distance, and as you approach, the close-up version will seemingly beam in as if from a Star Trek transporter beam.
But on each world, the environment, the destinations, the plants, and animals will all be generated randomly, mixing and matching from a pre-defined toolset. While this certainly allows for every different species to be unique, animals, plants, and rock formations all started feeling very similar as I'd see repeated elements time and time again. Creatures of different base types all interact with the work in the same way.
Possibly the greatest element of these discoveries is the ability to name them. While I didn't really take too much advantage of this, I have a couple notable stories. I botched my first planet naming it "t" as I accidentally hit "Done" instead of "Delete" to start anew. And somewhere out there in a vast reaches of the Euclid Galaxy is a system I dedicated to the guys at Kinda Funny labeled Kinda Funny Omega. Each planet is named for its five core members and I hope against hope and against all conceivable odds that some other Kinda Funny fan will somehow stumble upon this system at chuckle at the joke I left behind: the planet Nick_Scarpino_Omega.
The Vastness of Space
Every other element of the game is almost frustratingly basic. Mining for resources? Collect a mix of blue, red, green, yellow, and sometimes purple elements. These building blocks will recharge your shields, weapon, fuel, etc. but they are so plentiful, you'll have to actively try to strand yourself in a position where you would die from the "survival" aspect of the game. Combat? Slow and boring, on ground or in space, with no stakes. When you die, it won't necessarily because you're out-skilled but because ten ships happen to warp in an attack and there's no way to escape unless you're near enough to a planet or space station to evade them. But not to worry, because your stuff is right where you left it and easy to reclaim.
Even the game's interesting approach to learning alien languages word by word doesn't have enough meat on its bones to feel complete. The game's few alien species are all bland and only exist to serve as the most basic form of NPC puzzles. Even if you don't know a single word an alien is saying, the context provide and limited options will likely give you at worst a 1 out of 3 chance of correctly fulfilling the request. Learning key words only makes it easier. But even then, the rewards for solving these puzzles are usually just some credits, technology, or maybe and upgraded tool.
While I enjoyed the first few hours of No Man's Sky when I was experiencing everything for the first time, it quickly became far too repetitive for my taste. I ultimately find the game works best for me when played in small bursts days apart. Anything more than that and it ends up feeling like a pointless grind.
Additionally, the game has crashed more than any game I think I've ever played in recent years. It froze and crashed on me at least ten times last weekend alone. Fallout 4, as problematic as it was reported to me only crashed twice in all of the time I spent with it. I haven't delved in too much since the game received a patch earlier this week but it was worth noting that this was absolutely a broken game when it shipped. Unfortunate, but perhaps to be expected with such a small team working on such a massive game. If anything, I fault Sony more for letting it through certification in the state it was in than the developers who I'm sure would have rather had more time to polish.
If the idea of flying around from largely empty planet to largely empty planet in a largely empty galaxy sounds peaceful and interesting to you (and admittedly it occasionally does to me), then you may very well enjoy No Man's Sky. But don't go in expecting immensely deep gameplay as you won't find it in the game's current state. Perhaps someday if Hello Games decides to patch and support the game adding new features in the future. But right now, the game comes across more as a glorified tech demo showcasing the procedural-generation algorithms working under the hood than any kind of substantive game.