My Starfield impressions are so long that I'll just break it into parts, Lol.
Main Story (Full Spoilers)
Of the Bethesda titles I've played (Oblivion and Skyrim), it is easily their strongest main story they've written. Now I wouldn't call it anything "ground-breaking" but I did enjoy it and the places it took us. I thought it was well written and while I have seen better Sci-Fi stories, it leaves me wanting more and wanting answers to my questions. It starts a little slow while you're investigating the mystery but it was intriguing enough to push me further, it picks up a lot in the midway point and really picks up after a pivotal moment and the end series of quests were pretty awesome.
The final boss fight was way better than any boss fight in Oblivion or Skyrim. I thought it was nice that you could avoid the fight entirely via dialogue options but honestly the fight is worth doing more than making peace with these two assholes. The story overall went in a different direction than I expected but left me with a ton of questions, I did think that we would get aliens which we didn't but I'm still convinced it was aliens who made those artefacts. We still don't know who made them, why they made them, when they made them and how exactly they work.
The temples are bad though, the first temple was a cool moment, a bit of a thrill but then it repeats the same temple 10-20 times and ruins the impact. It reminded me of the dozens of Oblivion gates that you have to go through which honestly weren't that different except worse because the temples are the exact same every time. They're the centrepiece puzzle of the main story and vital for gaining powers yet feel so easy and uninspired past the first one, they should have mixed it up with different puzzles for each power.
Ending
I'm 50/50 on the ending, I rarely do NG+, in fact, I can't think of a single game which I've done NG+ in but Starfield's take on NG+ was interesting to me and almost convincing. I think from a gameplay perspective it was a cool idea and depending on how you want to roleplay it can make sense there too but I think they missed the mark a little, for a role-player such a myself, I want an clear game option to reject the Unity and not to have Sarah condescendingly tell me that I will change my mind and the mission is still marked incomplete, I want to reject the Unity.
If you're roleplaying other ways, the Unity would be brilliant but for me, I'm not allowed my decision. My decision is "fuck the Unity" and I can't think of anything worse than my character jumping through an endless loop of universe to universe until he's left feeling like nothing ultimately matters. I'd say that was even the story which Bethesda was trying to tell us, that in the end, it's all pointless. Accepting the Unity means losing your friends and family, those in the other universes are not your friends or family, they're another version of them.
I'd rather live with those losses than lose the bonds I've made with all my other alive friends only to replace them with different versions but the same face, it isn't the same. I'd rather my character died in that one universe that I have everything in but unfortunately that isn't an official option.
It's odd because I feel like the story backs up everything I'm saying. The Emissary, Hunter and Pilgrim are examples of this. These dudes passed through the Unity so much that they got stuck in an endless stupid cycle of constant fighting and going nowhere, nothing changes, nothing matters, they're more obsessed with the artefacts than finding out what put the artefacts there. They're both obsessed with power. The Emissary had good intentions but is ultimately a hypocrite who wants control, The Hunter is a bastard who killed my friend and gone crazy thinking he can kill anyone because nothing matters, Lol.
Having said what I said about the Emissary, I was a little conflicted in killing him, I think I would have actually kept him alive if I could kill only The Hunter and not him but The Hunter deserved to die and I was determined to kill him, if the Emissary has to die alongside him then so be it, and further thinking about The Emissary, I think he's just as much of a dick, they could have came to us from the start, avoided the conflict and the bloodshed and they were hypocritical. I felt manipulated by them being another version of my dead companion though which is probably where the wanting to keep them alive came from, Lol.
I think it should be an official option to say "fuck all that, fuck the Unity" and stay. The Unity corrupts and Bethesda's story shows that. There is no meaning to any relationship if you're just constantly jumping universe to universe. Nobody means anything anymore. You're in an endless pursuit of more power and either the player ends up like The Hunter where they're on NG+10 and nothing matters anymore or they grow sick of the endless pursuit and settle down like The Pilgrim. So why isn't it an official option? Lol.
Rejecting the Unity should give a game-over, mission complete. If I had my true roleplay option, I'd likely destroy the Unity and let the Aliens who made it be mad about it. When I rejected the Unity, it was nice to see some companions were surprised but relieved that I didn't go through it. Andreja confirmed my decision was right when she said "What if one of us returned but none others did, then they'd be alone" and she's right, I don't want to leave my family or friends in this universe or the relationships and legacy I've made.
Sidenote but it's funnier if you do Sarah's companion story because Sonia is now living with you. We plucked her off an uninhabited planet where she was getting by on her own but clearly lonely, her parents were dead, we convinced her to come with us and we'll take care of her, I plucked her from a "wild" life and dropped her in city life which she has never experienced and then my character would essentially say "Bye, I'm abandoning you now" and fuck off through the Unity, Lmfao. Sarah even annoyed me a little because she was all "Lol. You don't know what you're doing. You'll go through the Unity eventually and if you don't, I will" Gee! Fucking thanks, Sarah! So much for the marriage and love, Lmfao.
So I love the idea from a gameplay perspective and in some roleplay cases it would be great (if I ever decide I want to make an evil character then I'm going to wreck havoc in multiple universes) but I don't love that we don't have the official game-over option to reject it (they could still keep it there in case you change your mind), I like what Bethesda has done here overall but it's just missing that one choice for this specific roleplay option...
You can do NG+ and treat it only as a gameplay feature though, you can treat it as a story feature, or be like me and say "fuck off, I'm staying here" but I'll end up going through the Unity just for the achievement and reverting my save, Lol. It's a personal choice whether it's worth losing everything to you. My only gripe is no official option to reject it when the story so heavily shows the Unity corruption. The life of a Starborn sounds miserable and lonely. That's the irony of it, I actually like the story telling here, the more you enter the Unity, the more you either become like The Hunter or The Pilgrim.