Hiii, thanks for the ask!
Ok, I'm probably not going to be very original but. The Sun Station. Head in hands.
What ifst you've been expecting to find a way to stop the Sun from exploding from the moment you learnt about the supernova, because thats how it works in video games, right? You encounter a problem™ and it's your job as the protagonist to fix the problem™ and earn that sweet sweet delicious happy ending?
Then you learn Outer Wilds isn't that kind of story. It's not a game where you can save everyone - it's a game where the world is dying, has been dying for a long time, and all you can do is learning to let go.
(Something something, even the universe has a limited lifespan, and how you literally access the ending by unplugging the machine that keeps it alive - but do the timeloops even really count as living?) (Something something, end-of-life care overtreatment metaphors...)
(I also love love love that you're mislead to think it's the Nomai's fault too, but nope. There's no real antagonist in Outer Wilds except the unrelenting (completely natural) force of entropy.)
I like to think the Hatchling's presence at the end does matter (and the probe appearing in the next universe + the new alien species showing up if we met Solanum and the Prisoner does seem to imply it does).
(I don't think any of the other travelers are probably actually there, though... But who knows, with quantum shennanigans involved?)
Like, my understanding of how the Eye works is that basically, it starts emitting its signal as the universe starts to decay (thousands of years before the actual end, I guess, to have the spare time for space-faring civilizations to develop and find it), and once it's found the observer can help shape the new universe - maybe it's not even necessary for a new universe to be made that someone observes the Eye, but Outer Wilds, thematically, is as much about death as it is about transmission (especially generational - the fact that the finding of the Eye itself was a species-wide intergenerational journey...), so by managing to make the final trip you're basically leaving a legacy that will guide the future generations (the aliens of the new universe)'s first steps into the new world. Ouuuu.
(I think about 14.3 billion years and Echoes of the Eye a. a normal amount.)
(Related quotes I also think about a normal amount :
"Our curiosity goes with you on your journey. You walk in the steps of those that came before you, and your path guides those who will follow later." /
"The past is the past, now, but that's... You know, that's okay! It's never really gone completely. The future is built on the past, even if we don't get to see it.")
10/10 game, cheeks are rolling down my tears as we speak ::')